mixpanel.js

/*
 * Mixpanel JS Library v2.3.2
 *
 * Copyright 2012, Mixpanel, Inc. All Rights Reserved
 * http://mixpanel.com/
 *
 * Includes portions of Underscore.js
 * http://documentcloud.github.com/underscore/
 * (c) 2011 Jeremy Ashkenas, DocumentCloud Inc.
 * Released under the MIT License.
 */

// ==ClosureCompiler==
// @compilation_level ADVANCED_OPTIMIZATIONS
// @output_file_name mixpanel-2.3.min.js
// ==/ClosureCompiler==

/*
Will export window.mixpanel
*/

/*
SIMPLE STYLE GUIDE:

this.x == public function
this._x == internal - only use within this file
this.__x == private - only use within the class

Globals should be all caps
*/
(function (mixpanel) {

/*
 * Saved references to long variable names, so that closure compiler can
 * minimize file size.
 */
    var   ArrayProto        = Array.prototype
        , FuncProto         = Function.prototype
        , ObjProto          = Object.prototype
        , slice             = ArrayProto.slice
        , toString          = ObjProto.toString
        , hasOwnProperty    = ObjProto.hasOwnProperty
        , windowConsole     = window.console
        , navigator         = window.navigator
        , document          = window.document
        , userAgent         = navigator.userAgent;

/*
 * Constants
 */
/** @const */   var   PRIMARY_INSTANCE_NAME     = "mixpanel"
/** @const */       , SET_QUEUE_KEY             = "__mps"
/** @const */       , SET_ONCE_QUEUE_KEY        = "__mpso"
/** @const */       , ADD_QUEUE_KEY             = "__mpa"
/** @const */       , APPEND_QUEUE_KEY          = "__mpap"
/** @const */       , SET_ACTION                = "$set"
/** @const */       , SET_ONCE_ACTION           = "$set_once"
/** @const */       , ADD_ACTION                = "$add"
/** @const */       , APPEND_ACTION             = "$append"
// This key is deprecated, but we want to check for it to see whether aliasing is allowed.
/** @const */       , PEOPLE_DISTINCT_ID_KEY    = "$people_distinct_id"
/** @const */       , ALIAS_ID_KEY              = "__alias"
/** @const */       , CAMPAIGN_IDS_KEY          = "__cmpns"
/** @const */       , RESERVED_PROPERTIES       = [
                        SET_QUEUE_KEY,
                        SET_ONCE_QUEUE_KEY,
                        ADD_QUEUE_KEY,
                        APPEND_QUEUE_KEY,
                        PEOPLE_DISTINCT_ID_KEY,
                        ALIAS_ID_KEY,
                        CAMPAIGN_IDS_KEY
                    ];

/*
 * Dynamic... constants? Is that an oxymoron?
 */
    var HTTP_PROTOCOL = (("https:" == document.location.protocol) ? "https://" : "http://"),

        LIB_VERSION = '2.3.2',
        SNIPPET_VERSION = (mixpanel && mixpanel['__SV']) || 0,

        // http://hacks.mozilla.org/2009/07/cross-site-xmlhttprequest-with-cors/
        // https://developer.mozilla.org/en-US/docs/DOM/XMLHttpRequest#withCredentials
        USE_XHR = (window.XMLHttpRequest && 'withCredentials' in new XMLHttpRequest()),

        // IE<10 does not support cross-origin XHR's but script tags
        // with defer won't block window.onload; ENQUEUE_REQUESTS
        // should only be true for Opera<12
        ENQUEUE_REQUESTS = !USE_XHR && (userAgent.indexOf('MSIE') == -1) && (userAgent.indexOf('Mozilla') == -1);

/*
 * Closure-level globals
 */
    var   _                 = {}
        , DEBUG             = false
        , DEFAULT_CONFIG    = {
              "api_host":                   HTTP_PROTOCOL + 'api.mixpanel.com'
            , "cross_subdomain_cookie":     true
            , "cookie_name":                ""
            , "loaded":                     function() {}
            , "store_google":               true
            , "save_referrer":              true
            , "test":                       false
            , "verbose":                    false
            , "img":                        false
            , "track_pageview":             true
            , "debug":                      false
            , "track_links_timeout":        300
            , "cookie_expiration":          365
            , "upgrade":                    false
            , "disable_cookie":             false
            , "secure_cookie":              false
            , "ip":                         true
        }
        , DOM_LOADED        = false;

    // UNDERSCORE
    // Embed part of the Underscore Library

    (function() {
        var nativeBind    = FuncProto.bind,
            nativeForEach = ArrayProto.forEach,
            nativeIndexOf = ArrayProto.indexOf,
            nativeIsArray = Array.isArray,
            breaker = {};

        _.bind = function (func, context) {
            var args, bound;
            if (nativeBind && func.bind === nativeBind) return nativeBind.apply(func, slice.call(arguments, 1));
            if (!_.isFunction(func)) throw new TypeError;
            args = slice.call(arguments, 2);
            return bound = function() {
                if (!(this instanceof bound)) return func.apply(context, args.concat(slice.call(arguments)));
                ctor.prototype = func.prototype;
                var self = new ctor;
                ctor.prototype = null;
                var result = func.apply(self, args.concat(slice.call(arguments)));
                if (Object(result) === result) return result;
                return self;
            };
        };

        _.bind_instance_methods = function(obj) {
            for (var func in obj) {
                if (typeof(obj[func]) === 'function') {
                    obj[func] = _.bind(obj[func], obj);
                }
            }
        };

        /**
         * @param {*=} obj
         * @param {function(...[*])=} iterator
         * @param {Object=} context
         */
        var each = _.each = function(obj, iterator, context) {
            if (obj == null) return;
            if (nativeForEach && obj.forEach === nativeForEach) {
                obj.forEach(iterator, context);
            } else if (obj.length === +obj.length) {
                for (var i = 0, l = obj.length; i < l; i++) {
                    if (i in obj && iterator.call(context, obj[i], i, obj) === breaker) return;
                }
            } else {
                for (var key in obj) {
                    if (hasOwnProperty.call(obj, key)) {
                        if (iterator.call(context, obj[key], key, obj) === breaker) return;
                    }
                }
            }
        };

        _.escapeHTML = function(s) {
            var escaped = s;
            if (escaped && _.isString(escaped)) {
                escaped = escaped
                    .replace(/&/g, '&amp;')
                    .replace(/</g, '&lt;')
                    .replace(/>/g, '&gt;')
                    .replace(/"/g, '&quot;')
                    .replace(/'/g, '&#039;');
            }
            return escaped;
        };

        _.extend = function(obj) {
            each(slice.call(arguments, 1), function(source) {
                for (var prop in source) {
                    if (source[prop] !== void 0) obj[prop] = source[prop];
                }
            });
            return obj;
        };

        _.isArray = nativeIsArray || function(obj) {
            return toString.call(obj) === '[object Array]';
        };

        // from a comment on http://dbj.org/dbj/?p=286
        // fails on only one very rare and deliberate custom object:
        // var bomb = { toString : undefined, valueOf: function(o) { return "function BOMBA!"; }};
        _.isFunction = function (f) {
            try {
                return /^\s*\bfunction\b/.test(f);
            } catch (x) {
                return false;
            }
        };

        _.isArguments = function(obj) {
            return !!(obj && hasOwnProperty.call(obj, 'callee'));
        };

        _.toArray = function(iterable) {
            if (!iterable)                return [];
            if (iterable.toArray)         return iterable.toArray();
            if (_.isArray(iterable))      return slice.call(iterable);
            if (_.isArguments(iterable))  return slice.call(iterable);
            return _.values(iterable);
        };

        _.values = function(obj) {
            var results = [];
            if (obj == null) return results;
            each(obj, function(value) {
                results[results.length] = value;
            });
            return results;
        };

        _.identity = function(value) {
            return value;
        };

        _.include = function(obj, target) {
            var found = false;
            if (obj == null) return found;
            if (nativeIndexOf && obj.indexOf === nativeIndexOf) return obj.indexOf(target) != -1;
            each(obj, function(value) {
                if (found || (found = (value === target))) { return breaker; }
            });
            return found;
        };

        _.includes = function(str, needle) {
            return str.indexOf(needle) !== -1;
        };

    })();

    // Underscore Addons
    _.inherit = function(subclass, superclass) {
        subclass.prototype = new superclass();
        subclass.prototype.constructor = subclass;
        subclass.superclass = superclass.prototype;
        return subclass;
    };

    _.isObject = function(obj) {
        return (obj === Object(obj) && !_.isArray(obj));
    };

    _.isEmptyObject = function(obj) {
        if (_.isObject(obj)) {
            for (var key in obj) {
                if (hasOwnProperty.call(obj, key)) {
                    return false;
                }
            }
            return true;
        }
        return false;
    };

    _.isUndefined = function(obj) {
        return obj === void 0;
    };

    _.isString = function(obj) {
        return toString.call(obj) == '[object String]';
    };

    _.isDate = function(obj) {
        return toString.call(obj) == '[object Date]';
    };

    _.isNumber = function(obj) {
        return toString.call(obj) == '[object Number]';
    };

    _.encodeDates = function(obj) {
        _.each(obj, function(v, k) {
            if (_.isDate(v)) {
                obj[k] = _.formatDate(v);
            } else if (_.isObject(v)) {
                obj[k] = _.encodeDates(v); // recurse
            }
        });
        return obj;
    };

    _.formatDate = function(d) {
        // YYYY-MM-DDTHH:MM:SS in UTC
        function pad(n) {return n < 10 ? '0' + n : n}
        return d.getUTCFullYear() + '-'
            + pad(d.getUTCMonth() + 1) + '-'
            + pad(d.getUTCDate()) + 'T'
            + pad(d.getUTCHours()) + ':'
            + pad(d.getUTCMinutes()) + ':'
            + pad(d.getUTCSeconds());
    };

    _.safewrap = function(f) {
        return function() {
            try {
                f.apply(this, arguments);
            } catch(e) {
                console.critical('Implementation error. Please contact support@mixpanel.com.');
            }
        };
    };

    _.safewrap_class = function(klass, functions) {
        for (var i = 0; i < functions.length; i++) {
            klass.prototype[functions[i]] = _.safewrap(klass.prototype[functions[i]]);
        }
    };

    _.strip_empty_properties = function(p) {
        var ret = {};
        _.each(p, function(v, k) {
            if (_.isString(v) && v.length > 0) { ret[k] = v; }
        });
        return ret;
    };

    /*
     * this function returns a copy of object after truncating it.  If
     * passed an Array or Object it will iterate through obj and
     * truncate all the values recursively.
     */
    _.truncate = function(obj, length) {
        var ret;

        if (typeof(obj) === "string") {
            ret = obj.slice(0, length);
        } else if (_.isArray(obj)) {
            ret = [];
            _.each(obj, function(val) {
                ret.push(_.truncate(val, length));
            });
        } else if (_.isObject(obj)) {
            ret = {};
            _.each(obj, function(val, key) {
                ret[key] = _.truncate(val, length);
            });
        } else {
            ret = obj;
        }

        return ret;
    };

    _.JSONEncode = (function() {
        return function(mixed_val) {
            var indent;
            var value = mixed_val;
            var i;

            var quote = function (string) {
                var escapable = /[\\\"\x00-\x1f\x7f-\x9f\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g;
                var meta = {    // table of character substitutions
                    '\b': '\\b',
                    '\t': '\\t',
                    '\n': '\\n',
                    '\f': '\\f',
                    '\r': '\\r',
                    '"' : '\\"',
                    '\\': '\\\\'
                };

                escapable.lastIndex = 0;
                return escapable.test(string) ?
                '"' + string.replace(escapable, function (a) {
                    var c = meta[a];
                    return typeof c === 'string' ? c :
                    '\\u' + ('0000' + a.charCodeAt(0).toString(16)).slice(-4);
                }) + '"' :
                '"' + string + '"';
            };

            var str = function(key, holder) {
                var gap = '';
                var indent = '    ';
                var i = 0;          // The loop counter.
                var k = '';          // The member key.
                var v = '';          // The member value.
                var length = 0;
                var mind = gap;
                var partial = [];
                var value = holder[key];

                // If the value has a toJSON method, call it to obtain a replacement value.
                if (value && typeof value === 'object' &&
                    typeof value.toJSON === 'function') {
                    value = value.toJSON(key);
                }

                // What happens next depends on the value's type.
                switch (typeof value) {
                    case 'string':
                        return quote(value);

                    case 'number':
                        // JSON numbers must be finite. Encode non-finite numbers as null.
                        return isFinite(value) ? String(value) : 'null';

                    case 'boolean':
                    case 'null':
                        // If the value is a boolean or null, convert it to a string. Note:
                        // typeof null does not produce 'null'. The case is included here in
                        // the remote chance that this gets fixed someday.

                        return String(value);

                    case 'object':
                        // If the type is 'object', we might be dealing with an object or an array or
                        // null.
                        // Due to a specification blunder in ECMAScript, typeof null is 'object',
                        // so watch out for that case.
                        if (!value) {
                            return 'null';
                        }

                        // Make an array to hold the partial results of stringifying this object value.
                        gap += indent;
                        partial = [];

                        // Is the value an array?
                        if (toString.apply(value) === '[object Array]') {
                            // The value is an array. Stringify every element. Use null as a placeholder
                            // for non-JSON values.

                            length = value.length;
                            for (i = 0; i < length; i += 1) {
                                partial[i] = str(i, value) || 'null';
                            }

                            // Join all of the elements together, separated with commas, and wrap them in
                            // brackets.
                            v = partial.length === 0 ? '[]' :
                            gap ? '[\n' + gap +
                            partial.join(',\n' + gap) + '\n' +
                            mind + ']' :
                            '[' + partial.join(',') + ']';
                            gap = mind;
                            return v;
                        }

                        // Iterate through all of the keys in the object.
                        for (k in value) {
                            if (hasOwnProperty.call(value, k)) {
                                v = str(k, value);
                                if (v) {
                                    partial.push(quote(k) + (gap ? ': ' : ':') + v);
                                }
                            }
                        }

                        // Join all of the member texts together, separated with commas,
                        // and wrap them in braces.
                        v = partial.length === 0 ? '{}' :
                        gap ? '{' + partial.join(',') + '' +
                        mind + '}' : '{' + partial.join(',') + '}';
                        gap = mind;
                        return v;
                }
            };

            // Make a fake root object containing our value under the key of ''.
            // Return the result of stringifying the value.
            return str('', {
                '': value
            });
        };
    })();

    _.JSONDecode = (function() { // https://github.com/douglascrockford/JSON-js/blob/master/json_parse.js
        var at,     // The index of the current character
            ch,     // The current character
            escapee = {
                '"':  '"',
                '\\': '\\',
                '/':  '/',
                'b':  '\b',
                'f':  '\f',
                'n':  '\n',
                'r':  '\r',
                't':  '\t'
            },
            text,
            error = function (m) {
                throw {
                    name:    'SyntaxError',
                    message: m,
                    at:      at,
                    text:    text
                };
            },
            next = function (c) {
                // If a c parameter is provided, verify that it matches the current character.
                if (c && c !== ch) {
                    error("Expected '" + c + "' instead of '" + ch + "'");
                }
                // Get the next character. When there are no more characters,
                // return the empty string.
                ch = text.charAt(at);
                at += 1;
                return ch;
            },
            number = function () {
                // Parse a number value.
                var number,
                    string = '';

                if (ch === '-') {
                    string = '-';
                    next('-');
                }
                while (ch >= '0' && ch <= '9') {
                    string += ch;
                    next();
                }
                if (ch === '.') {
                    string += '.';
                    while (next() && ch >= '0' && ch <= '9') {
                        string += ch;
                    }
                }
                if (ch === 'e' || ch === 'E') {
                    string += ch;
                    next();
                    if (ch === '-' || ch === '+') {
                        string += ch;
                        next();
                    }
                    while (ch >= '0' && ch <= '9') {
                        string += ch;
                        next();
                    }
                }
                number = +string;
                if (!isFinite(number)) {
                    error("Bad number");
                } else {
                    return number;
                }
            },

            string = function () {
                // Parse a string value.
                var hex,
                    i,
                    string = '',
                    uffff;
                // When parsing for string values, we must look for " and \ characters.
                if (ch === '"') {
                    while (next()) {
                        if (ch === '"') {
                            next();
                            return string;
                        }
                        if (ch === '\\') {
                            next();
                            if (ch === 'u') {
                                uffff = 0;
                                for (i = 0; i < 4; i += 1) {
                                    hex = parseInt(next(), 16);
                                    if (!isFinite(hex)) {
                                        break;
                                    }
                                    uffff = uffff * 16 + hex;
                                }
                                string += String.fromCharCode(uffff);
                            } else if (typeof escapee[ch] === 'string') {
                                string += escapee[ch];
                            } else {
                                break;
                            }
                        } else {
                            string += ch;
                        }
                    }
                }
                error("Bad string");
            },
            white = function () {
                // Skip whitespace.
                while (ch && ch <= ' ') {
                    next();
                }
            },
            word = function () {
                // true, false, or null.
                switch (ch) {
                case 't':
                    next('t');
                    next('r');
                    next('u');
                    next('e');
                    return true;
                case 'f':
                    next('f');
                    next('a');
                    next('l');
                    next('s');
                    next('e');
                    return false;
                case 'n':
                    next('n');
                    next('u');
                    next('l');
                    next('l');
                    return null;
                }
                error("Unexpected '" + ch + "'");
            },
            value,  // Placeholder for the value function.
            array = function () {
                // Parse an array value.
                var array = [];

                if (ch === '[') {
                    next('[');
                    white();
                    if (ch === ']') {
                        next(']');
                        return array;   // empty array
                    }
                    while (ch) {
                        array.push(value());
                        white();
                        if (ch === ']') {
                            next(']');
                            return array;
                        }
                        next(',');
                        white();
                    }
                }
                error("Bad array");
            },
            object = function () {
                // Parse an object value.
                var key,
                    object = {};

                if (ch === '{') {
                    next('{');
                    white();
                    if (ch === '}') {
                        next('}');
                        return object;   // empty object
                    }
                    while (ch) {
                        key = string();
                        white();
                        next(':');
                        if (Object.hasOwnProperty.call(object, key)) {
                            error('Duplicate key "' + key + '"');
                        }
                        object[key] = value();
                        white();
                        if (ch === '}') {
                            next('}');
                            return object;
                        }
                        next(',');
                        white();
                    }
                }
                error("Bad object");
            };

        value = function () {
            // Parse a JSON value. It could be an object, an array, a string,
            // a number, or a word.
            white();
            switch (ch) {
            case '{':
                return object();
            case '[':
                return array();
            case '"':
                return string();
            case '-':
                return number();
            default:
                return ch >= '0' && ch <= '9' ? number() : word();
            }
        };

        // Return the json_parse function. It will have access to all of the
        // above functions and variables.
        return function (source) {
            var result;

            text = source;
            at = 0;
            ch = ' ';
            result = value();
            white();
            if (ch) {
                error("Syntax error");
            }

            return result;
        };
    })();

    _.base64Encode = function(data) {
        var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
        var o1, o2, o3, h1, h2, h3, h4, bits, i = 0, ac = 0, enc="", tmp_arr = [];

        if (!data) {
            return data;
        }

        data = _.utf8Encode(data);

        do { // pack three octets into four hexets
            o1 = data.charCodeAt(i++);
            o2 = data.charCodeAt(i++);
            o3 = data.charCodeAt(i++);

            bits = o1<<16 | o2<<8 | o3;

            h1 = bits>>18 & 0x3f;
            h2 = bits>>12 & 0x3f;
            h3 = bits>>6 & 0x3f;
            h4 = bits & 0x3f;

            // use hexets to index into b64, and append result to encoded string
            tmp_arr[ac++] = b64.charAt(h1) + b64.charAt(h2) + b64.charAt(h3) + b64.charAt(h4);
        } while (i < data.length);

        enc = tmp_arr.join('');

        switch( data.length % 3 ){
            case 1:
                enc = enc.slice(0, -2) + '==';
                break;
            case 2:
                enc = enc.slice(0, -1) + '=';
                break;
        }

        return enc;
    };

    _.utf8Encode = function(string) {
        string = (string+'').replace(/\r\n/g, "\n").replace(/\r/g, "\n");

        var utftext = "",
            start,
            end;
        var stringl = 0,
            n;

        start = end = 0;
        stringl = string.length;

        for (n = 0; n < stringl; n++) {
            var c1 = string.charCodeAt(n);
            var enc = null;

            if (c1 < 128) {
                end++;
            } else if((c1 > 127) && (c1 < 2048)) {
                enc = String.fromCharCode((c1 >> 6) | 192, (c1 & 63) | 128);
            } else {
                enc = String.fromCharCode((c1 >> 12) | 224, ((c1 >> 6) & 63) | 128, (c1 & 63) | 128);
            }
            if (enc !== null) {
                if (end > start) {
                    utftext += string.substring(start, end);
                }
                utftext += enc;
                start = end = n+1;
            }
        }

        if (end > start) {
            utftext += string.substring(start, string.length);
        }

        return utftext;
    };

    _.UUID = (function() {

        // Time/ticks information
        // 1*new Date() is a cross browser version of Date.now()
        var T = function() {
            var d = 1*new Date()
            , i = 0;

            // this while loop figures how many browser ticks go by
            // before 1*new Date() returns a new number, ie the amount
            // of ticks that go by per millisecond
            while (d == 1*new Date()) { i++; }

            return d.toString(16) + i.toString(16);
        };

        // Math.Random entropy
        var R = function() {
            return Math.random().toString(16).replace('.','');
        };

        // User agent entropy
        // This function takes the user agent string, and then xors
        // together each sequence of 8 bytes.  This produces a final
        // sequence of 8 bytes which it returns as hex.
        var UA = function(n) {
            var ua = userAgent, i, ch, buffer = [], ret = 0;

            function xor(result, byte_array) {
                var j, tmp = 0;
                for (j = 0; j < byte_array.length; j++) {
                    tmp |= (buffer[j] << j*8);
                }
                return result ^ tmp;
            }

            for (i = 0; i < ua.length; i++) {
                ch = ua.charCodeAt(i);
                buffer.unshift(ch & 0xFF);
                if (buffer.length >= 4) {
                    ret = xor(ret, buffer);
                    buffer = [];
                }
            }

            if (buffer.length > 0) { ret = xor(ret, buffer); }

            return ret.toString(16);
        };

        return function() {
            var se = (screen.height*screen.width).toString(16);
            return (T()+"-"+R()+"-"+UA()+"-"+se+"-"+T());
        };
    })();

    // _.isBlockedUA()
    // This is to block various web spiders from executing our JS and
    // sending false tracking data
    _.isBlockedUA = function(ua) {
        if (/(google web preview|baiduspider|yandexbot|bingbot|googlebot|yahoo! slurp)/i.test(ua)) {
            return true;
        }
        return false;
    };

    /**
     * @param {Object=} formdata
     * @param {string=} arg_separator
     */
    _.HTTPBuildQuery = function(formdata, arg_separator) {
        var key, use_val, use_key, tmp_arr = [];

        if (typeof(arg_separator) === "undefined") {
            arg_separator = '&';
        }

        _.each(formdata, function(val, key) {
            use_val = encodeURIComponent(val.toString());
            use_key = encodeURIComponent(key);
            tmp_arr[tmp_arr.length] = use_key + '=' + use_val;
        });

        return tmp_arr.join(arg_separator);
    };

    _.getQueryParam = function(url, param) {
        // Expects a raw URL

        param = param.replace(/[\[]/, "\\\[").replace(/[\]]/, "\\\]");
        var regexS = "[\\?&]" + param + "=([^&#]*)",
            regex = new RegExp( regexS ),
            results = regex.exec(url);
        if (results === null || (results && typeof(results[1]) !== 'string' && results[1].length)) {
            return '';
        } else {
            return decodeURIComponent(results[1]).replace(/\+/g, ' ');
        }
    };

    // _.cookie
    // Methods partially borrowed from quirksmode.org/js/cookies.html
    _.cookie = {
        get: function(name) {
            var nameEQ = name + "=";
            var ca = document.cookie.split(';');
            for(var i=0;i < ca.length;i++) {
                var c = ca[i];
                while (c.charAt(0)==' ') c = c.substring(1,c.length);
                if (c.indexOf(nameEQ) == 0) return decodeURIComponent(c.substring(nameEQ.length,c.length));
            }
            return null;
        },

        parse: function(name) {
            var cookie;
            try {
                cookie = _.JSONDecode(_.cookie.get(name)) || {};
            } catch (err) {}
            return cookie;
        },

        set: function(name, value, days, cross_subdomain, is_secure) {
            var cdomain = "", expires = "", secure = "";

            if (cross_subdomain) {
                var matches = document.location.hostname.match(/[a-z0-9][a-z0-9\-]+\.[a-z\.]{2,6}$/i)
                    , domain = matches ? matches[0] : '';

                cdomain   = ((domain) ? "; domain=." + domain : "");
            }

            if (days) {
                var date = new Date();
                date.setTime(date.getTime()+(days*24*60*60*1000));
                expires = "; expires=" + date.toGMTString();
            }

            if (is_secure) {
                secure = "; secure";
            }

            document.cookie = name + "=" + encodeURIComponent(value) + expires + "; path=/" + cdomain + secure;
        },

        remove: function(name, cross_subdomain) {
            _.cookie.set(name, '', -1, cross_subdomain);
        }
    };

    _.register_event = (function() {
        // written by Dean Edwards, 2005
        // with input from Tino Zijdel - crisp@xs4all.nl
        // with input from Carl Sverre - mail@carlsverre.com
        // with input from Mixpanel
        // http://dean.edwards.name/weblog/2005/10/add-event/
        // https://gist.github.com/1930440

        /**
        * @param {Object} element
        * @param {string} type
        * @param {function(...[*])} handler
        * @param {boolean=} oldSchool
        */
        var register_event = function(element, type, handler, oldSchool) {
            if (!element) {
                console.error("No valid element provided to register_event");
                return;
            }

            if (element.addEventListener && !oldSchool) {
                element.addEventListener(type, handler, false);
            } else {
                var ontype = 'on' + type;
                var old_handler = element[ontype]; // can be undefined
                element[ontype] = makeHandler(element, handler, old_handler);
            }
        };

        function makeHandler(element, new_handler, old_handlers) {
            var handler = function(event) {
                event = event || fixEvent(window.event);

                // this basically happens in firefox whenever another script
                // overwrites the onload callback and doesn't pass the event
                // object to previously defined callbacks.  All the browsers
                // that don't define window.event implement addEventListener
                // so the dom_loaded handler will still be fired as usual.
                if (!event) { return undefined; }

                var ret = true;
                var old_result, new_result;

                if (_.isFunction(old_handlers)) {
                    old_result = old_handlers(event);
                }
                new_result = new_handler.call(element, event);

                if ((false === old_result) || (false === new_result)) {
                    ret = false;
                }

                return ret;
            };

            return handler;
        };

        function fixEvent(event) {
            if (event) {
                event.preventDefault = fixEvent.preventDefault;
                event.stopPropagation = fixEvent.stopPropagation;
            }
            return event;
        };
        fixEvent.preventDefault = function() {
            this.returnValue = false;
        };
        fixEvent.stopPropagation = function() {
            this.cancelBubble = true;
        };

        return register_event;
    })();

    _.dom_query = (function() {
        /* document.getElementsBySelector(selector)
        - returns an array of element objects from the current document
        matching the CSS selector. Selectors can contain element names,
        class names and ids and can be nested. For example:

        elements = document.getElementsBySelector('div#main p a.external')

        Will return an array of all 'a' elements with 'external' in their
        class attribute that are contained inside 'p' elements that are
        contained inside the 'div' element which has id="main"

        New in version 0.4: Support for CSS2 and CSS3 attribute selectors:
        See http://www.w3.org/TR/css3-selectors/#attribute-selectors

        Version 0.4 - Simon Willison, March 25th 2003
        -- Works in Phoenix 0.5, Mozilla 1.3, Opera 7, Internet Explorer 6, Internet Explorer 5 on Windows
        -- Opera 7 fails

        Version 0.5 - Carl Sverre, Jan 7th 2013
        -- Now uses jQuery-esque `hasClass` for testing class name
        equality.  This fixes a bug related to '-' characters being
        considered not part of a 'word' in regex.
        */

        function getAllChildren(e) {
            // Returns all children of element. Workaround required for IE5/Windows. Ugh.
            return e.all ? e.all : e.getElementsByTagName('*');
        }

        var bad_whitespace = /[\t\r\n]/g;
        function hasClass(elem, selector) {
            var className = " " + selector + " ";
            return ((" " + elem.className + " ").replace(bad_whitespace, " ").indexOf(className) >= 0);
        }

        function getElementsBySelector(selector) {
            // Attempt to fail gracefully in lesser browsers
            if (!document.getElementsByTagName) {
                return new Array();
            }
            // Split selector in to tokens
            var tokens = selector.split(' ');
            var token;
            var currentContext = new Array(document);
            for (var i = 0; i < tokens.length; i++) {
                token = tokens[i].replace(/^\s+/,'').replace(/\s+$/,'');
                if (token.indexOf('#') > -1) {
                    // Token is an ID selector
                    var bits = token.split('#');
                    var tagName = bits[0];
                    var id = bits[1];
                    var element = document.getElementById(id);
                    if (!element || (tagName && element.nodeName.toLowerCase() != tagName)) {
                        // element not found or tag with that ID not found, return false
                        return new Array();
                    }
                    // Set currentContext to contain just this element
                    currentContext = new Array(element);
                    continue; // Skip to next token
                }
                if (token.indexOf('.') > -1) {
                    // Token contains a class selector
                    var bits = token.split('.');
                    var tagName = bits[0];
                    var className = bits[1];
                    if (!tagName) {
                        tagName = '*';
                    }
                    // Get elements matching tag, filter them for class selector
                    var found = new Array;
                    var foundCount = 0;
                    for (var h = 0; h < currentContext.length; h++) {
                        var elements;
                        if (tagName == '*') {
                            elements = getAllChildren(currentContext[h]);
                        } else {
                            elements = currentContext[h].getElementsByTagName(tagName);
                        }
                        for (var j = 0; j < elements.length; j++) {
                            found[foundCount++] = elements[j];
                        }
                    }
                    currentContext = new Array;
                    var currentContextIndex = 0;
                    for (var k = 0; k < found.length; k++) {
                        if (found[k].className
                            && _.isString(found[k].className)   // some SVG elements have classNames which are not strings
                            && hasClass(found[k], className)
                        ) {
                            currentContext[currentContextIndex++] = found[k];
                        }
                    }
                    continue; // Skip to next token
                }
                // Code to deal with attribute selectors
                if (token.match(/^(\w*)\[(\w+)([=~\|\^\$\*]?)=?"?([^\]"]*)"?\]$/)) {
                    var tagName = RegExp.$1;
                    var attrName = RegExp.$2;
                    var attrOperator = RegExp.$3;
                    var attrValue = RegExp.$4;
                    if (!tagName) {
                        tagName = '*';
                    }
                    // Grab all of the tagName elements within current context
                    var found = new Array;
                    var foundCount = 0;
                    for (var h = 0; h < currentContext.length; h++) {
                        var elements;
                        if (tagName == '*') {
                            elements = getAllChildren(currentContext[h]);
                        } else {
                            elements = currentContext[h].getElementsByTagName(tagName);
                        }
                        for (var j = 0; j < elements.length; j++) {
                            found[foundCount++] = elements[j];
                        }
                    }
                    currentContext = new Array;
                    var currentContextIndex = 0;
                    var checkFunction; // This function will be used to filter the elements
                    switch (attrOperator) {
                        case '=': // Equality
                            checkFunction = function(e) { return (e.getAttribute(attrName) == attrValue); };
                            break;
                        case '~': // Match one of space seperated words
                            checkFunction = function(e) { return (e.getAttribute(attrName).match(new RegExp('\\b'+attrValue+'\\b'))); };
                            break;
                        case '|': // Match start with value followed by optional hyphen
                            checkFunction = function(e) { return (e.getAttribute(attrName).match(new RegExp('^'+attrValue+'-?'))); };
                            break;
                        case '^': // Match starts with value
                            checkFunction = function(e) { return (e.getAttribute(attrName).indexOf(attrValue) == 0); };
                            break;
                        case '$': // Match ends with value - fails with "Warning" in Opera 7
                            checkFunction = function(e) { return (e.getAttribute(attrName).lastIndexOf(attrValue) == e.getAttribute(attrName).length - attrValue.length); };
                            break;
                        case '*': // Match ends with value
                            checkFunction = function(e) { return (e.getAttribute(attrName).indexOf(attrValue) > -1); };
                            break;
                        default :
                            // Just test for existence of attribute
                            checkFunction = function(e) { return e.getAttribute(attrName); };
                    }
                    currentContext = new Array;
                    currentContextIndex = 0;
                    for (var k = 0; k < found.length; k++) {
                        if (checkFunction(found[k])) {
                            currentContext[currentContextIndex++] = found[k];
                        }
                    }
                    // alert('Attribute Selector: '+tagName+' '+attrName+' '+attrOperator+' '+attrValue);
                    continue; // Skip to next token
                }
                // If we get here, token is JUST an element (not a class or ID selector)
                tagName = token;
                var found = new Array;
                var foundCount = 0;
                for (var h = 0; h < currentContext.length; h++) {
                    var elements = currentContext[h].getElementsByTagName(tagName);
                    for (var j = 0; j < elements.length; j++) {
                        found[foundCount++] = elements[j];
                    }
                }
                currentContext = found;
            }
            return currentContext;
        };

        return getElementsBySelector;
    })();

    _.info = {
        campaignParams: function() {
            var campaign_keywords = 'utm_source utm_medium utm_campaign utm_content utm_term'.split(' ')
                , kw = ''
                , params = {};
            _.each(campaign_keywords, function(kwkey) {
                kw = _.getQueryParam(document.URL, kwkey);
                if (kw.length) {
                    params[kwkey] = kw;
                }
            });

            return params;
        },

        searchEngine: function(referrer) {
            if (referrer.search('https?://(.*)google.([^/?]*)') === 0) {
                return 'google';
            } else if (referrer.search('https?://(.*)bing.com') === 0) {
                return 'bing';
            } else if (referrer.search('https?://(.*)yahoo.com') === 0) {
                return 'yahoo';
            } else if (referrer.search('https?://(.*)duckduckgo.com') === 0) {
                return 'duckduckgo';
            } else {
                return null;
            }
        },

        searchInfo: function(referrer) {
            var search = _.info.searchEngine(referrer)
                , param = (search != "yahoo") ? "q" : "p"
                , ret = {};

            if (search !== null) {
                ret["$search_engine"] = search;

                var keyword = _.getQueryParam(referrer, param);
                if (keyword.length) {
                    ret["mp_keyword"] = keyword;
                }
            }

            return ret;
        },

        /**
         * This function detects which browser is running this script.
         * The order of the checks are important since many user agents
         * include key words used in later checks.
         */
        browser: function(user_agent, vendor, opera) {
            var vendor = vendor || ''; // vendor is undefined for at least IE9
            if (opera) {
                if (_.includes(user_agent, "Mini")) {
                    return "Opera Mini";
                }
                return "Opera";
            } else if (/(BlackBerry|PlayBook|BB10)/i.test(user_agent)) {
                return 'BlackBerry';
            } else if (_.includes(user_agent, "FBIOS")) {
                return "Facebook Mobile";
            } else if (_.includes(user_agent, "Chrome")) {
                return "Chrome";
            } else if (_.includes(user_agent, "CriOS")) {
                return "Chrome iOS";
            } else if (_.includes(vendor, "Apple")) {
                if (_.includes(user_agent, "Mobile")) {
                    return "Mobile Safari";
                }
                return "Safari";
            } else if (_.includes(user_agent, "Android")) {
                return "Android Mobile";
            } else if (_.includes(user_agent, "Konqueror")) {
                return "Konqueror";
            } else if (_.includes(user_agent, "Firefox")) {
                return "Firefox";
            } else if (_.includes(user_agent, "MSIE") || _.includes(user_agent, "Trident/")) {
                return "Internet Explorer";
            } else if (_.includes(user_agent, "Gecko")) {
                return "Mozilla";
            } else {
                return "";
            }
        },

        os: function() {
            var a = userAgent;
            if (/Windows/i.test(a)) {
                if (/Phone/.test(a)) { return 'Windows Mobile'; }
                return 'Windows';
            } else if (/(iPhone|iPad|iPod)/.test(a)) {
                return 'iOS';
            } else if (/Android/.test(a)) {
                return 'Android';
            } else if (/(BlackBerry|PlayBook|BB10)/i.test(a)) {
                return 'BlackBerry';
            } else if (/Mac/i.test(a)) {
                return 'Mac OS X';
            } else if (/Linux/.test(a)) {
                return 'Linux';
            } else {
                return '';
            }
        },

        device: function(user_agent) {
            if (/iPad/.test(user_agent)) {
                return 'iPad';
            } else if (/iPod/.test(user_agent)) {
                return 'iPod Touch';
            } else if (/iPhone/.test(user_agent)) {
                return 'iPhone';
            } else if (/(BlackBerry|PlayBook|BB10)/i.test(user_agent)) {
                return 'BlackBerry';
            } else if (/Windows Phone/i.test(user_agent)) {
                return 'Windows Phone';
            } else if (/Android/.test(user_agent)) {
                return 'Android';
            } else {
                return '';
            }
        },

        referringDomain: function(referrer) {
            var split = referrer.split("/");
            if (split.length >= 3) {
                return split[2];
            }
            return "";
        },

        properties: function() {
            return _.extend(_.strip_empty_properties({
                '$os': _.info.os(),
                '$browser': _.info.browser(userAgent, navigator.vendor, window.opera),
                '$referrer': document.referrer,
                '$referring_domain': _.info.referringDomain(document.referrer),
                '$device': _.info.device(userAgent)
            }), {
                '$screen_height': screen.height,
                '$screen_width': screen.width,
                'mp_lib': 'web',
                '$lib_version': LIB_VERSION
            });
        },

        people_properties: function() {
            return _.strip_empty_properties({
                '$os': _.info.os(),
                '$browser': _.info.browser(userAgent, navigator.vendor, window.opera)
            });
        },

        pageviewInfo: function(page) {
            return _.strip_empty_properties({
                'mp_page': page
                , 'mp_referrer': document.referrer
                , 'mp_browser': _.info.browser(userAgent, navigator.vendor, window.opera)
                , 'mp_platform': _.info.os()
            });
        }
    };

    // Console override
    var console = {
        /** @type {function(...[*])} */
        log: function() {
            if (DEBUG && !_.isUndefined(windowConsole) && windowConsole) {
                try {
                    windowConsole.log.apply(windowConsole, arguments);
                } catch(err) {
                    _.each(arguments, function(arg) {
                        windowConsole.log(arg);
                    });
                }
            }
        },
        /** @type {function(...[*])} */
        error: function() {
            if (DEBUG && !_.isUndefined(windowConsole) && windowConsole) {
                var args = ["Mixpanel error:"].concat(_.toArray(arguments));
                try {
                    windowConsole.error.apply(windowConsole, args);
                } catch(err) {
                    _.each(args, function(arg) {
                        windowConsole.error(arg);
                    });
                }
            }
        },
        /** @type {function(...[*])} */
        critical: function() {
            if (!_.isUndefined(windowConsole) && windowConsole) {
                var args = ["Mixpanel error:"].concat(_.toArray(arguments));
                try {
                    windowConsole.error.apply(windowConsole, args);
                } catch(err) {
                    _.each(args, function(arg) {
                        windowConsole.error(arg);
                    });
                }
            }
        }
    };

    /**
     * DomTracker Object
     * @constructor
     */
    var DomTracker = function() {};

    // interface
    DomTracker.prototype.create_properties = function() {};
    DomTracker.prototype.event_handler = function() {};
    DomTracker.prototype.after_track_handler = function() {};

    DomTracker.prototype.init = function(mixpanel_instance) {
        this.mp = mixpanel_instance;
        return this;
    };

    /**
     * @param {string} query
     * @param {string} event_name
     * @param {Object=} properties
     * @param {function(...[*])=} user_callback
     */
    DomTracker.prototype.track = function(query, event_name, properties, user_callback) {
        var that = this
        , elements = _.dom_query(query);

        if (elements.length == 0) {
            console.error("The DOM query (" + query + ") returned 0 elements");
            return;
        }

        _.each(elements, function(element) {
            _.register_event(element, this.override_event, function(e) {
                var options = {}
                    , props = that.create_properties(properties, this)
                    , timeout = that.mp.get_config("track_links_timeout");

                that.event_handler(e, this, options);

                // in case the mixpanel servers don't get back to us in time
                window.setTimeout(that.track_callback(user_callback, props, options, true), timeout);

                // fire the tracking event
                that.mp.track(event_name, props, that.track_callback(user_callback, props, options));
            });
        }, this);

        return true;
    };

    /**
     * @param {function(...[*])} user_callback
     * @param {Object} props
     * @param {boolean=} timeout_occured
     */
    DomTracker.prototype.track_callback = function(user_callback, props, options, timeout_occured) {
        timeout_occured = timeout_occured || false;
        var that = this;

        return function() {
            // options is referenced from both callbacks, so we can have
            // a "lock" of sorts to ensure only one fires
            if (options.callback_fired) { return; }
            options.callback_fired = true;

            if (user_callback && user_callback(timeout_occured, props) === false) {
                // user can prevent the default functionality by
                // returning false from their callback
                return;
            }

            that.after_track_handler(props, options, timeout_occured);
        };
    };

    DomTracker.prototype.create_properties = function(properties, element) {
        var props;

        if (typeof(properties) === "function") {
            props = properties(element);
        } else {
            props = _.extend({}, properties);
        }

        return props;
    };

    /**
     * LinkTracker Object
     * @constructor
     * @extends DomTracker
     */
    var LinkTracker = function() {
        this.override_event = "click";
    };
    _.inherit(LinkTracker, DomTracker);

    LinkTracker.prototype.create_properties = function(properties, element) {
        var props = LinkTracker.superclass.create_properties.apply(this, arguments);

        if (element.href) { props["url"] = element.href; }

        return props;
    };

    LinkTracker.prototype.event_handler = function(evt, element, options) {
        options.new_tab = (evt.which === 2 || evt.metaKey || element.target === "_blank");
        options.href = element.href;

        if (!options.new_tab) {
            evt.preventDefault();
        }
    };

    LinkTracker.prototype.after_track_handler = function(props, options, timeout_occured) {
        if (options.new_tab) { return; }

        setTimeout(function() {
            window.location = options.href;
        }, 0);
    };

    /**
     * FormTracker Object
     * @constructor
     * @extends DomTracker
     */
    var FormTracker = function() {
        this.override_event = "submit";
    };
    _.inherit(FormTracker, DomTracker);

    FormTracker.prototype.event_handler = function(evt, element, options) {
        options.element = element;
        evt.preventDefault();
    };

    FormTracker.prototype.after_track_handler = function(props, options, timeout_occured) {
        setTimeout(function() {
            options.element.submit();
        }, 0);
    };

    /**
     * Mixpanel Cookie Object
     * @constructor
     */
    var MixpanelCookie = function(config) {
        this['props'] = {};
        this.campaign_params_saved = false;

        if (config['cookie_name']) {
            this.name = "mp_" + config['cookie_name'];
        } else {
            this.name = "mp_" + config['token'] + "_mixpanel";
        }
        this.load();
        this.update_config(config);
        this.upgrade(config);
        this.save();
    };

    MixpanelCookie.prototype.properties = function() {
        var p = {};
        // Filter out reserved properties
        _.each(this['props'], function(v, k) {
            if (!_.include(RESERVED_PROPERTIES, k)) {
                p[k] = v;
            }
        });
        return p;
    };

    MixpanelCookie.prototype.load = function() {
        if (this.disabled) { return; }

        var cookie = _.cookie.parse(this.name);

        if (cookie) {
            this['props'] = _.extend({}, cookie);
        }
    };

    MixpanelCookie.prototype.upgrade = function(config) {
        var should_upgrade = config['upgrade'],
            old_cookie_name,
            old_cookie;

        if (should_upgrade) {
            old_cookie_name = "mp_super_properties";
            // Case where they had a custom cookie name before.
            if (typeof(should_upgrade) === "string") {
                old_cookie_name = should_upgrade;
            }

            old_cookie = _.cookie.parse(old_cookie_name);

            // remove the cookie
            _.cookie.remove(old_cookie_name);
            _.cookie.remove(old_cookie_name, true);

            if (old_cookie) {
                this['props'] = _.extend(
                    this['props'],
                    old_cookie['all'],
                    old_cookie['events']
                );
            }
        }

        if (!config['cookie_name'] && config['name'] !== 'mixpanel') {
            // special case to handle people with cookies of the form
            // mp_TOKEN_INSTANCENAME from the first release of this library
            old_cookie_name = "mp_" + config['token'] + "_" + config['name'];
            old_cookie = _.cookie.parse(old_cookie_name);

            if (old_cookie) {
                _.cookie.remove(old_cookie_name);
                _.cookie.remove(old_cookie_name, true);

                // Save the prop values that were in the cookie from before -
                // this should only happen once as we delete the old one.
                this.register_once(old_cookie);
            }
        }
    };

    MixpanelCookie.prototype.save = function() {
        if (this.disabled) { return; }
        this._expire_notification_campaigns();
        _.cookie.set(
            this.name,
            _.JSONEncode(this['props']),
            this.expire_days,
            this.cross_subdomain,
            this.secure
        );
    };

    MixpanelCookie.prototype.remove = function() {
        // remove both domain and subdomain cookies
        _.cookie.remove(this.name, false);
        _.cookie.remove(this.name, true);
    };

    // removes the cookie and deletes all loaded data
    // forced name for tests
    MixpanelCookie.prototype.clear = function() {
        this.remove();
        this['props'] = {};
    };

    /**
     * @param {Object} props
     * @param {*=} default_value
     * @param {number=} days
     */
    MixpanelCookie.prototype.register_once = function(props, default_value, days) {
        if (_.isObject(props)) {
            if (typeof(default_value) === 'undefined') { default_value = "None"; }
            this.expire_days = (typeof(days) === 'undefined') ? this.default_expiry : days;

            _.each(props, function(val, prop) {
                if (!this['props'][prop] || this['props'][prop] === default_value) {
                    this['props'][prop] = val;
                }
            }, this);

            this.save();

            return true;
        }
        return false;
    };

    /**
     * @param {Object} props
     * @param {number=} days
     */
    MixpanelCookie.prototype.register = function(props, days) {
        if (_.isObject(props)) {
            this.expire_days = (typeof(days) === 'undefined') ? this.default_expiry : days;

            _.extend(this['props'], props);

            this.save();

            return true;
        }
        return false;
    };

    MixpanelCookie.prototype.unregister = function(prop) {
        if (prop in this['props']) {
            delete this['props'][prop];
            this.save();
        }
    };

    MixpanelCookie.prototype._expire_notification_campaigns = function() {
        var campaigns_shown = this['props'][CAMPAIGN_IDS_KEY],
            EXPIRY_TIME = DEBUG ? 60 * 1000 : 60 * 60 * 1000; // 1 minute (DEBUG) / 1 hour (PDXN)
        if (!campaigns_shown) {
            return;
        }
        for (var campaign_id in campaigns_shown) {
            if (1 * new Date() - campaigns_shown[campaign_id] > EXPIRY_TIME) {
                delete campaigns_shown[campaign_id];
            }
        }
        if (_.isEmptyObject(campaigns_shown)) {
            delete this['props'][CAMPAIGN_IDS_KEY];
        }
    };

    MixpanelCookie.prototype.update_campaign_params = function() {
        if (!this.campaign_params_saved) {
            this.register_once(_.info.campaignParams());
            this.campaign_params_saved = true;
        }
    };

    MixpanelCookie.prototype.update_search_keyword = function(referrer) {
        this.register(_.info.searchInfo(referrer));
    };

    // EXPORTED METHOD, we test this directly.
    MixpanelCookie.prototype.update_referrer_info = function(referrer) {
        // If referrer doesn't exist, we want to note the fact that it was type-in traffic.
        this.register_once({
            "$initial_referrer": referrer || "$direct",
            "$initial_referring_domain": _.info.referringDomain(referrer) || "$direct"
        }, "");
    };

    MixpanelCookie.prototype.get_referrer_info = function() {
        return _.strip_empty_properties({
            '$initial_referrer': this['props']['$initial_referrer'],
            '$initial_referring_domain': this['props']['$initial_referring_domain']
        });
    };

    // safely fills the passed in object with the cookies properties,
    // does not override any properties defined in both
    // returns the passed in object
    MixpanelCookie.prototype.safe_merge = function(props) {
        _.each(this['props'], function(val, prop) {
            if (!(prop in props)) {
                props[prop] = val;
            }
        });

        return props;
    };

    MixpanelCookie.prototype.update_config = function(config) {
        this.default_expiry = this.expire_days = config['cookie_expiration'];
        this.set_disabled(config['disable_cookie']);
        this.set_cross_subdomain(config['cross_subdomain_cookie']);
        this.set_secure(config['secure_cookie']);
    };

    MixpanelCookie.prototype.set_disabled = function(disabled) {
        this.disabled = disabled;
        if (this.disabled) {
            this.remove();
        }
    };

    MixpanelCookie.prototype.set_cross_subdomain = function(cross_subdomain) {
        if (cross_subdomain !== this.cross_subdomain) {
            this.cross_subdomain = cross_subdomain;
            this.remove();
            this.save();
        }
    };

    MixpanelCookie.prototype.get_cross_subdomain = function() {
        return this.cross_subdomain;
    };

    MixpanelCookie.prototype.set_secure = function(secure) {
        if (secure !== this.secure) {
            this.secure = secure ? true : false;
            this.remove();
            this.save();
        }
    };

    MixpanelCookie.prototype._add_to_people_queue = function(queue, data) {
        var q_key = this._get_queue_key(queue),
            q_data = data[queue],
            set_q = this._get_or_create_queue(SET_ACTION),
            set_once_q = this._get_or_create_queue(SET_ONCE_ACTION),
            add_q = this._get_or_create_queue(ADD_ACTION),
            append_q = this._get_or_create_queue(APPEND_ACTION, []);

        if (q_key === SET_QUEUE_KEY) {
            // Update the set queue - we can override any existing values
            _.extend(set_q, q_data);
            // if there was a pending increment, override it
            // with the set.
            this._pop_from_people_queue(ADD_ACTION, q_data);
        } else if (q_key === SET_ONCE_QUEUE_KEY) {
            // only queue the data if there is not already a set_once call for it.
            _.each(q_data, function(v, k) {
                if (!(k in set_once_q)) {
                    set_once_q[k] = v;
                }
            });
        } else if (q_key === ADD_QUEUE_KEY) {
            _.each(q_data, function(v, k) {
                // If it exists in the set queue, increment
                // the value
                if (k in set_q) {
                    set_q[k] += v;
                } else {
                    // If it doesn't exist, update the add
                    // queue
                    if (!(k in add_q)) {
                        add_q[k] = 0;
                    }
                    add_q[k] += v;
                }
            }, this);
        } else if (q_key === APPEND_QUEUE_KEY) {
            append_q.push(q_data);
        }

        console.log("MIXPANEL PEOPLE REQUEST (QUEUED, PENDING IDENTIFY):");
        console.log(data);

        this.save();
    };

    MixpanelCookie.prototype._pop_from_people_queue = function(queue, data) {
        var q = this._get_queue(queue);
        if (!_.isUndefined(q)) {
            _.each(data, function(v, k) {
                delete q[k];
            }, this);

            this.save();
        }
    };

    MixpanelCookie.prototype._get_queue_key = function(queue) {
        if (queue === SET_ACTION) {
            return SET_QUEUE_KEY;
        } else if (queue === SET_ONCE_ACTION) {
            return SET_ONCE_QUEUE_KEY;
        } else if (queue === ADD_ACTION) {
            return ADD_QUEUE_KEY;
        } else if (queue === APPEND_ACTION) {
            return APPEND_QUEUE_KEY;
        } else {
            console.error("Invalid queue:", queue);
        }
    };

    MixpanelCookie.prototype._get_queue = function(queue) {
        return this['props'][this._get_queue_key(queue)];
    };
    MixpanelCookie.prototype._get_or_create_queue = function(queue, default_val) {
        var key = this._get_queue_key(queue),
            default_val = _.isUndefined(default_val) ? {} : default_val;

        return this['props'][key] || (this['props'][key] = default_val);
    };

    /**
     * create_mplib(token:string, config:object, name:string)
     *
     * This function is used by the init method of MixpanelLib objects
     * as well as the main initializer at the end of the JSLib (that
     * initializes document.mixpanel as well as any additional instances
     * declared before this file has loaded).
     */
    var create_mplib = function(token, config, name) {
        var instance, target = (name === PRIMARY_INSTANCE_NAME) ? mixpanel : mixpanel[name];

        if (target && !_.isArray(target)) {
            console.error("You have already initialized " + name);
            return;
        }

        instance = new MixpanelLib();
        instance._init(token, config, name);

        instance['people'] = new MixpanelPeople();
        instance['people']._init(instance);

        // if any instance on the page has debug = true, we set the
        // global debug to be true
        DEBUG = DEBUG || instance.get_config('debug');

        // if target is not defined, we called init after the lib already
        // loaded, so there won't be an array of things to execute
        if (!_.isUndefined(target)) {
            // Crunch through the people queue first - we queue this data up &
            // flush on identify, so it's better to do all these operations first
            instance._execute_array.call(instance['people'], target['people']);
            instance._execute_array(target);
        }

        return instance;
    };

    /**
     * Mixpanel Library Object
     * @constructor
     */
    var MixpanelLib = function() { };

    // Initialization methods

    /**
     * This function initialize a new instance of the Mixpanel tracking object.
     * All new instances are added to the main mixpanel object as sub properties (such as
     * mixpanel.your_library_name) and also returned by this function.  If you wanted
     * to define a second instance on the page you would do it like so:
     *
     *      mixpanel.init("new token", { your: "config" }, "library_name")
     *
     * and use it like this:
     *
     *      mixpanel.library_name.track(...)
     *
     * @param {String} token   Your Mixpanel API token
     * @param {Object} [config]  A dictionary of config options to override
     * @param {String} [name]    The name for the new mixpanel instance that you want created
     */
    MixpanelLib.prototype.init = function (token, config, name) {
        if (typeof(name) === "undefined") {
            console.error("You must name your new library: init(token, config, name)");
            return;
        }
        if (name === PRIMARY_INSTANCE_NAME) {
            console.error("You must initialize the main mixpanel object right after you include the Mixpanel js snippet");
            return;
        }

        var instance = create_mplib(token, config, name);
        mixpanel[name] = instance;
        instance._loaded();

        return instance;
    };

    // mixpanel._init(token:string, config:object, name:string)
    //
    // This function sets up the current instance of the mixpanel
    // library.  The difference between this method and the init(...)
    // method is this one initializes the actual instance, whereas the
    // init(...) method sets up a new library and calls _init on it.
    //
    MixpanelLib.prototype._init = function(token, config, name) {
        this['__loaded'] = true;
        this['config'] = {};

        this.set_config(_.extend({}, DEFAULT_CONFIG, config, {
              "name": name
            , "token": token
            , "callback_fn": ((name === PRIMARY_INSTANCE_NAME) ? name : PRIMARY_INSTANCE_NAME + '.' + name) + '._jsc'
        }));

        this['_jsc'] = function() {};

        this.__dom_loaded_queue = [];
        this.__request_queue = [];
        this.__disabled_events = [];
        this._flags = {
              "disable_all_events": false
            , "identify_called": false
        };

        this['cookie'] = new MixpanelCookie(this['config']);
        this.register_once({'distinct_id': _.UUID()}, "");
    };

    // Private methods

    MixpanelLib.prototype._loaded = function() {
        this.get_config('loaded')(this);

        // this happens after so a user can call identify/name_tag in
        // the loaded callback
        if (this.get_config('track_pageview')) {
            this.track_pageview();
        }
    };

    MixpanelLib.prototype._dom_loaded = function() {
        _.each(this.__dom_loaded_queue, function(item) {
            this._track_dom.apply(this, item);
        }, this);
        _.each(this.__request_queue, function(item) {
            this._send_request.apply(this, item);
        }, this);
        delete this.__dom_loaded_queue;
        delete this.__request_queue;
    };

    MixpanelLib.prototype._track_dom = function(DomClass, args) {
        if (this.get_config('img')) {
            console.error("You can't use DOM tracking functions with img = true.");
            return false;
        }

        if (!DOM_LOADED) {
            this.__dom_loaded_queue.push([DomClass, args]);
            return false;
        }

        var dt = new DomClass().init(this);
        return dt.track.apply(dt, args);
    };

    /**
     * _prepare_callback() should be called by callers of _send_request for use
     * as the callback argument.
     *
     * If there is no callback, this returns null.
     * If we are going to make XHR/XDR requests, this returns a function.
     * If we are going to use script tags, this returns a string to use as the
     * callback GET param.
     */
    MixpanelLib.prototype._prepare_callback = function(callback, data) {
        if (_.isUndefined(callback)) {
            return null;
        }

        if (USE_XHR) {
            var callback_function = function(response) {
                callback(response, data);
            };
            return callback_function;
        } else {
            // if the user gives us a callback, we store as a random
            // property on this instances jsc function and update our
            // callback string to reflect that.
            var jsc = this['_jsc']
                , randomized_cb = '' + Math.floor(Math.random() * 100000000)
                , callback_string = this.get_config('callback_fn') + '["' + randomized_cb + '"]';
            jsc[randomized_cb] = function(response) {
                delete jsc[randomized_cb];
                callback(response, data);
            };
            return callback_string;
        }
    };

    MixpanelLib.prototype._send_request = function(url, data, callback) {
        if (ENQUEUE_REQUESTS) {
            this.__request_queue.push(arguments);
            return;
        }

        // needed to correctly format responses
        var verbose_mode = this.get_config('verbose');
        if (data['verbose']) { verbose_mode = true; }

        if (this.get_config('test')) { data['test'] = 1; }
        if (verbose_mode) { data['verbose'] = 1; }
        if (this.get_config('img')) { data['img'] = 1; }
        if (!USE_XHR) {
            if (callback) {
                data['callback'] = callback;
            } else if (verbose_mode || this.get_config('test')) {
                // Verbose output (from verbose mode, or an error in test mode) is a json blob,
                // which by itself is not valid javascript. Without a callback, this verbose output will
                // cause an error when returned via jsonp, so we force a no-op callback param.
                // See the ECMA script spec: http://www.ecma-international.org/ecma-262/5.1/#sec-12.4
                data['callback'] = '(function(){})';
            }
        }

        data['ip'] = this.get_config('ip')?1:0;
        data['_'] = new Date().getTime().toString();
        url += '?' + _.HTTPBuildQuery(data);

        if ('img' in data) {
            var img = document.createElement("img");
                img.src = url;
            document.body.appendChild(img);
        } else if (USE_XHR) {
            var req = new XMLHttpRequest();
            req.open("GET", url, true);
            // send the mp_optout cookie
            // withCredentials cannot be modified until after calling .open on Android and Mobile Safari
            req.withCredentials = true;
            req.onreadystatechange = function (e) {
                if (req.readyState === 4) { // XMLHttpRequest.DONE == 4, except in safari 4
                    if (req.status === 200) {
                        if (callback) {
                            if (verbose_mode) { callback(_.JSONDecode(req.responseText)); }
                            else { callback(Number(req.responseText)); }
                        }
                    } else {
                        var error = 'Bad HTTP status: ' + req.status + ' ' + req.statusText;
                        console.error(error);
                        if (callback) {
                            if (verbose_mode) { callback({ status: 0, error: error }); }
                            else { callback(0); }
                        }
                    }
                }
            };
            req.send(null);
        } else {
            var script = document.createElement("script");
                script.type = "text/javascript";
                script.async = true;
                script.defer = true;
                script.src = url;
            var s = document.getElementsByTagName("script")[0];
            s.parentNode.insertBefore(script, s);
        }
    };

    /**
     * _execute_array() deals with processing any mixpanel function
     * calls that were called before the Mixpanel library were loaded
     * (and are thus stored in an array so they can be called later)
     *
     * Note: we fire off all the mixpanel function calls && user defined
     * functions BEFORE we fire off mixpanel tracking calls.  This is so
     * identify/register/set_config calls can properly modify early
     * tracking calls.
     *
     * @param {Array} array
     */
    MixpanelLib.prototype._execute_array = function(array) {
        var fn_name, alias_calls = [], other_calls = [], tracking_calls = [];
        _.each(array, function(item) {
            if (item) {
                fn_name = item[0];
                if (typeof(item) === "function") {
                    item.call(this);
                } else if (_.isArray(item) && fn_name === 'alias') {
                    alias_calls.push(item);
                } else if (_.isArray(item) && fn_name.indexOf('track') != -1 && typeof(this[fn_name]) === "function") {
                    tracking_calls.push(item);
                } else {
                    other_calls.push(item);
                }
            }
        }, this);

        var execute = function(calls, context) {
            _.each(calls, function(item) {
                this[item[0]].apply(this, item.slice(1));
            }, context);
        };

        execute(alias_calls, this);
        execute(other_calls, this);
        execute(tracking_calls, this);
    };

    /**
     * push() keeps the standard async-array-push
     * behavior around after the lib is loaded.
     * This is only useful for external integrations that
     * do not wish to rely on our convenience methods
     * (created in the snippet). Good example is Optimizely.
     *
     * ### Usage:
     *     mixpanel.push(['register', { a: 'b' }]);
     *
     * @param {Array} item A [function_name, args...] array to be executed
     */
    MixpanelLib.prototype.push = function(item) {
        this._execute_array([item]);
    };

    /**
     * Disable events on the Mixpanel object.  If passed no arguments,
     * this function disables tracking of any event.  If passed an
     * array of event names, those events will be disabled, but other
     * events will continue to be tracked.
     *
     * Note: this function doesn't stop regular mixpanel functions from
     * firing such as register and name_tag.
     *
     * @param {Array} [events] An array of event names to disable
     */
    MixpanelLib.prototype.disable = function(events) {
        if (typeof(events) === 'undefined') {
            this._flags.disable_all_events = true;
        } else {
            this.__disabled_events = this.__disabled_events.concat(events);
        }
    };

    /**
     * Track an event.  This is the most important Mixpanel function and
     * the one you will be using the most.
     *
     * ### Usage:
     *
     *     // track an event named "Registered"
     *     mixpanel.track("Registered", {"Gender": "Male", "Age": 21});
     *
     * For tracking link clicks or form submissions, see mixpanel.track_links or mixpanel.track_forms.
     *
     * @param {String} event_name The name of the event. This can be anything the user does - "Button Click", "Sign Up", "Item Purchased", etc.
     * @param {Object} [properties] A set of properties to include with the event you're sending. These describe the user who did the event or details about the event itself.
     * @param {Function} [callback] If provided, the callback function will be called after tracking the event.
     */
    MixpanelLib.prototype.track = function(event_name, properties, callback) {
        if (typeof(event_name) === "undefined") {
            console.error("No event name provided to mixpanel.track");
            return;
        }

        if (_.isBlockedUA(userAgent)
        ||  this._flags.disable_all_events
        ||  _.include(this.__disabled_events, event_name)) {
            if (typeof(callback) !== 'undefined') { callback(0); }
            return;
        }

        // set defaults
        properties = properties || {};
        properties['token'] = properties.token || this.get_config('token');

        // update cookie
        this['cookie'].update_search_keyword(document.referrer);

        if (this.get_config('store_google')) { this['cookie'].update_campaign_params(); }
        if (this.get_config('save_referrer')) { this['cookie'].update_referrer_info(document.referrer); }

        // note: extend writes to the first object, so lets make sure we
        // don't write to the cookie properties object and info
        // properties object by passing in a new object

        // update properties with pageview info and super-properties
        properties = _.extend(
            {}
            , _.info.properties()
            , this['cookie'].properties()
            , properties
        );

        var data = {
              'event': event_name
            , 'properties': properties
        };

        var truncated_data  = _.truncate(data, 255)
            , json_data     = _.JSONEncode(truncated_data)
            , encoded_data  = _.base64Encode(json_data);

        console.log("MIXPANEL REQUEST:");
        console.log(truncated_data);

        this._send_request(
            this.get_config('api_host') + "/track/",
            { 'data': encoded_data },
            this._prepare_callback(callback, truncated_data)
        );

        return truncated_data;
    };

    /**
     * Track a page view event, which is currently ignored by the server.
     * This function is called by default on page load unless the
     * track_pageview configuration variable is false.
     *
     * @param {String} [page] The url of the page to record. If you don't include this, it defaults to the current url.
     * @api private
     */
    MixpanelLib.prototype.track_pageview = function(page) {
        if (typeof(page) === "undefined") { page = document.location.href; }
        this.track("mp_page_view", _.info.pageviewInfo(page));
    };

    /**
     * Track clicks on a set of document elements.  Selector must be a
     * valid query. Elements must exist on the page at the time track_links is called.
     *
     * ### Usage:
     *
     *     // track click for link id #nav
     *     mixpanel.track_links("#nav", "Clicked Nav Link");
     *
     * ### Notes:
     *
     * This function will wait up to 300 ms for the Mixpanel
     * servers to respond. If they have not responded by that time
     * it will head to the link without ensuring that your event
     * has been tracked.  To configure this timeout please see the
     * mixpanel.set_config docs below.
     *
     * If you pass a function in as the properties argument, the
     * function will receive the DOMElement which triggered the
     * event as an argument.  You are expected to return an object
     * from the function; any properties defined on this object
     * will be sent to mixpanel as event properties.
     *
     * @type {Function}
     * @param {String} query A valid DOM query
     * @param {String} event_name The name of the event to track
     * @param {Object|Function} [properties] A properties object or function that returns a dictionary of properties when passed a DOMElement
     */
    MixpanelLib.prototype.track_links = function() {
        return this._track_dom.call(this, LinkTracker, arguments);
    };

    /**
     * Tracks form submissions. Selector must be a valid query.
     *
     * ### Usage:
     *
     *     // track submission for form id "register"
     *     mixpanel.track_forms("#register", "Created Account");
     *
     * ### Notes:
     *
     * This function will wait up to 300 ms for the mixpanel
     * servers to respond, if they have not responded by that time
     * it will head to the link without ensuring that your event
     * has been tracked.  To configure this timeout please see the
     * mixpanel.set_config docs below.
     *
     * If you pass a function in as the properties argument, the
     * function will receive the DOMElement which triggered the
     * event as an argument.  You are expected to return an object
     * from the function; any properties defined on this object
     * will be sent to mixpanel as event properties.
     *
     * @type {Function}
     * @param {String} query  A valid DOM query
     * @param {String} event_name The name of the event to track
     * @param {Object|Function} [properties] This can be a set of properties, or a function that returns a set of properties after being passed a DOMElement
     */
    MixpanelLib.prototype.track_forms = function() {
        return this._track_dom.call(this, FormTracker, arguments);
    };

    /**
     * Register a set of super properties, which are included with all
     * events.  This will overwrite previous super property values.
     *
     * @param {Object} properties An associative array of properties to store about the user
     * @param {Number} [days] How many days since the user's last visit to store the super properties
     */
    MixpanelLib.prototype.register = function(props, days) {
        this['cookie'].register(props, days);
    };

    /**
     * Register a set of super properties only once.  This will not
     * overwrite previous super property values, unlike register().
     *
     * ### Notes:
     *
     * If default_value is specified, current super properties
     * with that value will be overwritten.
     *
     * @param {Object} properties An associative array of properties to store about the user
     * @param {*} [default_value] Value to override if already set in super properties (ex: "False") Default: "None"
     * @param {Number} [days] How many days since the users last visit to store the super properties
     */
    MixpanelLib.prototype.register_once = function(props, default_value, days) {
        this['cookie'].register_once(props, default_value, days);
    };

    /**
     * Delete a super property stored with the current user.
     *
     * @param {String} property The name of the super property to remove
     */
    MixpanelLib.prototype.unregister = function(property) {
        this['cookie'].unregister(property);
    };

    MixpanelLib.prototype._register_single = function(prop, value) {
        var props = {};
        props[prop] = value;
        this.register(props);
    };

    /**
     * Identify a user with a unique id.  All subsequent
     * actions caused by this user will be tied to this identity.  This
     * property is used to track unique visitors.  If the method is
     * never called, then unique visitors will be identified by a UUID
     * generated the first time they visit the site.
     *
     * ### Note:
     *
     * You can call this function to overwrite a previously set
     * unique id for the current user.  Mixpanel cannot translate
     * between ids at this time, so when you change a users id
     * they will appear to be a new user.
     *
     * @param {String} unique_id A string that uniquely identifies a user
     */
    MixpanelLib.prototype.identify = function(unique_id, _set_callback, _add_callback, _append_callback, _set_once_callback) {
        // Optional Parameters
        //  _set_callback:function  A callback to be run if and when the People set queue is flushed
        //  _add_callback:function  A callback to be run if and when the People add queue is flushed
        //  _append_callback:function  A callback to be run if and when the People append queue is flushed
        //  _set_once_callback:function  A callback to be run if and when the People set_once queue is flushed

        // identify only changes the distinct id if it doesn't match either the existing or the alias;
        // if it's new, blow away the alias as well.
        if (unique_id != this.get_distinct_id() && unique_id != this.get_property(ALIAS_ID_KEY)) {
            this.unregister(ALIAS_ID_KEY);
            this._register_single('distinct_id', unique_id);
        }
        this._check_and_handle_notifications(this.get_distinct_id());
        this._flags.identify_called = true;
        // Flush any queued up people requests
        this['people']._flush(_set_callback, _add_callback, _append_callback, _set_once_callback);
    };

    /**
     * Returns the current distinct id of the user. This is either the id automatically
     * generated by the library or the id that has been passed by a call to mixpanel.identify
     */
    MixpanelLib.prototype.get_distinct_id = function() {
        return this.get_property('distinct_id');
    };

    /**
     * Create an alias, which Mixpanel will use to link two distinct_ids going forward (not retroactively).
     *  Multiple aliases can map to the same original ID, but not vice-versa. Aliases can also be chained - the
     *  following is a valid scenario:
     *
     *      mixpanel.alias("new_id", "existing_id");
     *      ...
     *      mixpanel.alias("newer_id", "new_id");
     *
     * If the original ID is not passed in, we will use the current distinct_id - probably the auto-generated GUID.
     *
     * @param {String} alias A unique identifier that you want to use for this user in the future.
     * @param {String} [original] The current identifier being used for this user.
     */
    MixpanelLib.prototype.alias = function(alias, original) {
        // If the $people_distinct_id key exists in the cookie, there has been a previous
        // mixpanel.people.identify() call made for this user. It is VERY BAD to make an alias with
        // this ID, as it will duplicate users.
        if (alias === this.get_property(PEOPLE_DISTINCT_ID_KEY)) {
            console.critical("Attempting to create alias for existing People user - aborting.");
            return -2;
        }

        var _this = this;
        if (_.isUndefined(original)) {
            original = this.get_distinct_id();
        }
        if (alias !== original) {
            this._register_single(ALIAS_ID_KEY, alias);
            return this.track("$create_alias", { "alias": alias, "distinct_id": original }, function(response) {
                // Flush the people queue
                _this.identify(alias);
            });
        } else {
            console.error("alias matches current distinct_id - skipping api call.");
            this.identify(alias);
            return -1;
        }
    };

    /**
     * Provide a string to recognize the user by.  The string passed to
     * this method will appear in the Mixpanel Streams product rather
     * than an automatically generated name.  Name tags do not have to
     * be unique.
     *
     * This value will only be included in Streams data.
     *
     * @param {String} name_tag A human readable name for the user
     * @api private
     */
    MixpanelLib.prototype.name_tag = function(name_tag) {
        this._register_single('mp_name_tag', name_tag);
    };

    /**
     * Update the configuration of a mixpanel library instance.
     *
     * The default config is:
     *
     *     {
     *       // super properties span subdomains
     *       cross_subdomain_cookie:     true
     *
     *       // super properties cookie name
     *       cookie_name:                ""
     *
     *       // super properties cookie expiration (in days)
     *       cookie_expiration:          365
     *
     *       // should we track a page view on page load
     *       track_pageview:             true
     *
     *       // the amount of time track_links will
     *       // wait for Mixpanel's servers to respond
     *       track_links_timeout:        300
     *
     *       // if this is true, the mixpanel cookie will be deleted,
     *       // and no user persistence will take place
     *       disable_cookie:             false
     *
     *       // if this is true, the mixpanel cookie will be marked as
     *       // secure, meaning it will only be transmitted over https
     *       secure_cookie:              false
     *
     *       // if you set upgrade to be true, the library will check for a
     *       // cookie from our old js library and import super
     *       // properties from it, then the old cookie is deleted
     *       // The upgrade config option only works in the initialization, so
     *       // make sure you set it when you create the library.
     *       upgrade:                    false
     *     }
     *
     *
     * @param {Object} config A dictionary of new configuration values to update
     */
    MixpanelLib.prototype.set_config = function(config) {
        if (_.isObject(config)) {
            _.extend(this['config'], config);
            if (this['cookie']) { this['cookie'].update_config(this['config']); }
            DEBUG = DEBUG || this.get_config('debug');
        }
    };

    /**
     * returns the current config object for the library.
     */
    MixpanelLib.prototype.get_config = function(prop_name) {
        return this['config'][prop_name];
    };

    /**
     * Returns the value of the super property named property_name. If no such
     * property is set, get_property will return the undefined value.
     *
     * @param {String} property_name The name of the super property you want to retrieve
     */
    MixpanelLib.prototype.get_property = function(property_name) {
        return this['cookie']['props'][property_name];
    };

    MixpanelLib.prototype.toString = function() {
        var name = this.get_config("name");
        if (name !== PRIMARY_INSTANCE_NAME) {
            name = PRIMARY_INSTANCE_NAME + "." + name;
        }
        return name;
    };

    MixpanelLib.prototype._check_and_handle_notifications = function(distinct_id) {
        if (!distinct_id || this._flags.identify_called || this.get_config('disable_notifications')) {
            return;
        }

        console.log("MIXPANEL NOTIFICATION CHECK");

        var data = {
            'verbose':     true,
            'version':     '1',
            'lib':         'web',
            'token':       this.get_config('token'),
            'distinct_id': distinct_id
        };
        var self = this;
        this._send_request(
            this.get_config('api_host') + '/decide/',
            data,
            this._prepare_callback(function(r) {
                if (r['notifications'] && r['notifications'].length > 0) {
                    self._show_notification.call(self, r['notifications'][0]);
                }
            })
        );
    };

    MixpanelLib.prototype._show_notification = function(notification_data) {
        var notification = new MPNotif(notification_data, this);
        notification.show();
    };

    /**
     * Mixpanel People Object
     * @constructor
     */
    var MixpanelPeople = function(){ };

    MixpanelPeople.prototype._init = function(mixpanel) {
        this._mixpanel = mixpanel;
    };

    /*
     * Set properties on a user record.
     *
     * ### Usage:
     *
     *     mixpanel.people.set('gender', 'm');
     *
     *     // or set multiple properties at once
     *     mixpanel.people.set({
     *         'Company': 'Acme',
     *         'Plan': 'Premium',
     *         'Upgrade date': new Date()
     *     });
     *     // properties can be strings, integers, dates, or lists
     *
     * @param {Object|String} prop If a string, this is the name of the property. If an object, this is an associative array of names and values.
     * @param {*} [to] A value to set on the given property name
     * @param {Function} [callback] If provided, the callback will be called after the tracking event
     */
    MixpanelPeople.prototype.set = function(prop, to, callback) {
        var data = {};
        var $set = {};
        if (_.isObject(prop)) {
            _.each(prop, function(v, k) {
                // We will get these ourselves
                if (k == '$distinct_id' || k == '$token') {
                    return;
                } else {
                    $set[k] = v;
                }
            });
            callback = to;
        } else {
            $set[prop] = to;
        }

        // make sure that the referrer info has been updated and saved
        if (this._get_config('save_referrer')) {
            this._mixpanel.cookie.update_referrer_info(document.referrer);
        }

        // update $set object with default people properties
        $set = _.extend({}
            , _.info.people_properties()
            , this._mixpanel.cookie.get_referrer_info()
            , $set
        );

        data[SET_ACTION] = $set;

        return this._send_request(data, callback);
    };

    /*
     * Set properties on a user record, only if they do not yet exist.
     *
     * ### Usage:
     *
     *     mixpanel.people.set_once('First Login Date', new Date());
     *
     *     // or set multiple properties at once
     *     mixpanel.people.set_once({
     *         'First Login Date': new Date(),
     *         'Starting Plan': 'Premium'
     *     });
     *
     *     // properties can be strings, integers or dates
     *
     * @param {Object|String} prop If a string, this is the name of the property. If an object, this is an associative array of names and values.
     * @param {*} [to] A value to set on the given property name
     * @param {Function} [callback] If provided, the callback will be called after the tracking event
     */
    MixpanelPeople.prototype.set_once = function(prop, to, callback) {
        var data = {};
        var $set_once = {};
        if (_.isObject(prop)) {
            _.each(prop, function(v, k) {
                // We will get these ourselves
                if (k == '$distinct_id' || k == '$token') {
                    return;
                } else {
                    $set_once[k] = v;
                }
            });
            callback = to;
        } else {
            $set_once[prop] = to;
        }
        data[SET_ONCE_ACTION] = $set_once;
        return this._send_request(data, callback);
    };

    /*
     * Increment/decrement numeric people analytics properties.
     *
     * ### Usage:
     *
     *     mixpanel.people.increment('page_views', 1);
     *
     *     // or, for convenience, if you're just incrementing a counter by 1, you can
     *     // simply do
     *     mixpanel.people.increment('page_views');
     *
     *     // to decrement a counter, pass a negative number
     *     mixpanel.people.increment('credits_left': -1);
     *
     *     // like mixpanel.people.set(), you can increment multiple properties at once:
     *     mixpanel.people.increment({
     *         counter1: 1,
     *         counter2: 1
     *     });
     *
     * @param {Object|String} prop If a string, this is the name of the property. If an object, this is an associative array of names and numeric values.
     * @param {Number} [by] An amount to increment the given property
     * @param {Function} [callback] If provided, the callback will be called after the tracking event
     */
    MixpanelPeople.prototype.increment = function(prop, by, callback) {
        var data = {};
        var $add = {};
        if (_.isObject(prop)) {
            _.each(prop, function(v, k) {
                if (k == '$distinct_id' || k == '$token') {
                    return;
                } else if (isNaN(parseFloat(v))) {
                    console.error("Invalid increment value passed to mixpanel.people.increment - must be a number");
                    return;
                } else {
                    $add[k] = v;
                }
            });
            callback = by;
        } else {
            // convenience: mixpanel.people.increment('property'); will
            // increment 'property' by 1
            if (_.isUndefined(by)) {
                by = 1;
            }
            $add[prop] = by;
        }
        data[ADD_ACTION] = $add;

        return this._send_request(data, callback);
    };

    /*
     * Append a value to a list-valued people analytics property.
     *
     * ### Usage:
     *
     *     // append a value to a list, creating it if needed
     *     mixpanel.people.append('pages_visited', 'homepage');
     *
     *     // like mixpanel.people.set(), you can append multiple properties at once:
     *     mixpanel.people.append({
     *         list1: 'bob',
     *         list2: 123
     *     });
     *
     * @param {Object|String} prop If a string, this is the name of the property. If an object, this is an associative array of names and numeric values.
     * @param {*} [value] An item to append to the list
     * @param {Function} [callback] If provided, the callback will be called after the tracking event
     */
    MixpanelPeople.prototype.append = function(list_name, value, callback) {
        var data = {};
        var $append = {};
        if (_.isObject(list_name)) {
            _.each(list_name, function(v, k) {
                if (k == '$distinct_id' || k == '$token') {
                    return;
                } else {
                    $append[k] = v;
                }
            });
            callback = value;
        } else {
            $append[list_name] = value;
        }
        data[APPEND_ACTION] = $append;

        return this._send_request(data, callback);
    };

    /*
     * Record that you have charged the current user a certain amount
     * of money. Charges recorded with track_charge will appear in the
     * Mixpanel revenue report.
     *
     * ### Usage:
     *
     *     // charge a user $50
     *     mixpanel.people.track_charge(50);
     *
     *     // charge a user $30.50 on the 2nd of january
     *     mixpanel.people.track_charge(30.50, { '$time': new Date('jan 1 2012') });
     *
     * @param {Number} amount The amount of money charged to the current user
     * @param {Object} [properties] An associative array of properties associated with the charge
     * @param {Function} [callback] If provided, the callback will be called when the server responds
     */
    MixpanelPeople.prototype.track_charge = function(amount, properties, callback) {
        if (!_.isNumber(amount)) {
            amount = parseFloat(amount);
            if (isNaN(amount)) {
                console.error("Invalid value passed to mixpanel.people.track_charge - must be a number");
                return;
            }
        }

        return this.append('$transactions', _.extend({
            '$amount': amount
        }, properties), callback);
    };

    /*
     * Permanently clear all revenue report transactions from the
     * current user's people analytics profile.
     *
     * ### Usage:
     *
     *     mixpanel.people.clear_charges();
     *
     * @param {Function} [callback] If provided, the callback will be called after the tracking event
     */
    MixpanelPeople.prototype.clear_charges = function(callback) {
        return this.set('$transactions', [], callback);
    };

    /*
     * Permanently deletes the current people analytics profile from
     * Mixpanel (using the current distinct_id).
     *
     * ### Usage:
     *
     *     // remove the all data you have stored about the current user
     *     mixpanel.people.delete_user();
     *
     */
    MixpanelPeople.prototype.delete_user = function() {
        if (!this._identify_called()) {
            console.error('mixpanel.people.delete_user() requires you to call identify() first');
            return;
        }
        var data = {'$delete': this._mixpanel.get_distinct_id()};
        return this._send_request(data);
    };

    MixpanelPeople.prototype.toString = function() {
        return this._mixpanel.toString() + ".people";
    };

    MixpanelPeople.prototype._send_request = function(data, callback) {
        data['$token'] = this._get_config('token');
        data['$distinct_id'] = this._mixpanel.get_distinct_id();

        var date_encoded_data = _.encodeDates(data)
          , truncated_data    = _.truncate(date_encoded_data, 255)
          , json_data         = _.JSONEncode(date_encoded_data)
          , encoded_data      = _.base64Encode(json_data);

        if (!this._identify_called()) {
            this._enqueue(data);
            if (!_.isUndefined(callback)) {
                if (this._get_config('verbose')) {
                    callback({ status: -1, error: null });
                } else {
                    callback(-1);
                }
            }
            return truncated_data;
        }

        console.log("MIXPANEL PEOPLE REQUEST:");
        console.log(truncated_data);

        this._mixpanel._send_request(
            this._get_config('api_host') + '/engage/',
            { 'data': encoded_data },
            this._mixpanel._prepare_callback(callback, truncated_data)
        );

        return truncated_data;
    };

    MixpanelPeople.prototype._get_config = function(conf_var) {
        return this._mixpanel.get_config(conf_var);
    };

    MixpanelPeople.prototype._identify_called = function() {
        return this._mixpanel._flags.identify_called === true;
    };

    // Queue up engage operations if identify hasn't been called yet.
    MixpanelPeople.prototype._enqueue = function(data) {
        if (SET_ACTION in data) {
            this._mixpanel.cookie._add_to_people_queue(SET_ACTION, data);
        } else if (SET_ONCE_ACTION in data) {
            this._mixpanel.cookie._add_to_people_queue(SET_ONCE_ACTION, data);
        } else if (ADD_ACTION in data) {
            this._mixpanel.cookie._add_to_people_queue(ADD_ACTION, data);
        } else if (APPEND_ACTION in data) {
            this._mixpanel.cookie._add_to_people_queue(APPEND_ACTION, data);
        } else {
            console.error("Invalid call to _enqueue():", data);
        }
    };

    // Flush queued engage operations - order does not matter,
    // and there are network level race conditions anyway
    MixpanelPeople.prototype._flush = function(_set_callback, _add_callback, _append_callback, _set_once_callback) {
        var _this = this,
            $set_queue = _.extend({}, this._mixpanel.cookie._get_queue(SET_ACTION)),
            $set_once_queue = _.extend({}, this._mixpanel.cookie._get_queue(SET_ONCE_ACTION)),
            $add_queue = _.extend({}, this._mixpanel.cookie._get_queue(ADD_ACTION)),
            $append_queue = this._mixpanel.cookie._get_queue(APPEND_ACTION);

        if (!_.isUndefined($set_queue) && _.isObject($set_queue) && !_.isEmptyObject($set_queue)) {
            _this._mixpanel.cookie._pop_from_people_queue(SET_ACTION, $set_queue);
            this.set($set_queue, function(response, data) {
                // on bad response, we want to add it back to the queue
                if (response == 0) {
                    _this._mixpanel.cookie._add_to_people_queue(SET_ACTION, $set_queue);
                }
                if (!_.isUndefined(_set_callback)) {
                    _set_callback(response, data);
                }
            });
        }

        if (!_.isUndefined($set_once_queue) && _.isObject($set_once_queue) && !_.isEmptyObject($set_once_queue)) {
            _this._mixpanel.cookie._pop_from_people_queue(SET_ONCE_ACTION, $set_once_queue);
            this.set_once($set_once_queue, function(response, data) {
                // on bad response, we want to add it back to the queue
                if (response == 0) {
                    _this._mixpanel.cookie._add_to_people_queue(SET_ONCE_ACTION, $set_once_queue);
                }
                if (!_.isUndefined(_set_once_callback)) {
                    _set_once_callback(response, data);
                }
            });
        }

        if (!_.isUndefined($add_queue) && _.isObject($add_queue) && !_.isEmptyObject($add_queue)) {
            _this._mixpanel.cookie._pop_from_people_queue(ADD_ACTION, $add_queue);
            this.increment($add_queue, function(response, data) {
                // on bad response, we want to add it back to the queue
                if (response == 0) {
                    _this._mixpanel.cookie._add_to_people_queue(ADD_ACTION, $add_queue);
                }
                if (!_.isUndefined(_add_callback)) {
                    _add_callback(response, data);
                }
            });
        }

        // we have to fire off each $append individually since there is
        // no concat method server side
        if (!_.isUndefined($append_queue) && _.isArray($append_queue) && $append_queue.length) {
            for (var i = $append_queue.length - 1; i >= 0; i--) {
                var $append_item = $append_queue.pop();
                _this.append($append_item, function(response, data) {
                    if (response == 0) {
                        _this._mixpanel.cookie._add_to_people_queue(APPEND_ACTION, $append_item);
                    }
                    if (!_.isUndefined(_append_callback)) { _append_callback(response, data); }
                });
            };
            // Save the shortened append queue
            _this._mixpanel.cookie.save();
        }
    };

    // Internal class for notification display
    MixpanelLib._Notification = function(notif_data, mixpanel_instance) {
        _.bind_instance_methods(this);

        this.mixpanel = mixpanel_instance;
        this.cookie   = this.mixpanel['cookie'];

        this.campaign_id = _.escapeHTML(notif_data['id']);
        this.message_id  = _.escapeHTML(notif_data['message_id']);

        this.body            = (_.escapeHTML(notif_data['body']) || '').replace(/\n/g, '<br/>');
        this.cta             = _.escapeHTML(notif_data['cta']) || 'Close';
        this.dest_url        = _.escapeHTML(notif_data['cta_url']) || null;
        this.image_url       = _.escapeHTML(notif_data['image_url']) || null;
        this.notif_type      = _.escapeHTML(notif_data['type']) || 'takeover';
        this.style           = _.escapeHTML(notif_data['style']) || 'light';
        this.thumb_image_url = _.escapeHTML(notif_data['thumb_image_url']) || null;
        this.title           = _.escapeHTML(notif_data['title']) || '';
        this.video_url       = _.escapeHTML(notif_data['video_url']) || null;
        this.video_width     = MPNotif.VIDEO_WIDTH;
        this.video_height    = MPNotif.VIDEO_HEIGHT;

        this.clickthrough = true;
        if (!this.dest_url) {
            this.dest_url = '#dismiss';
            this.clickthrough = false;
        }

        this.mini = this.notif_type === 'mini';
        if (!this.mini) {
            this.notif_type = 'takeover';
        }
        this.notif_width = !this.mini ? MPNotif.NOTIF_WIDTH : MPNotif.NOTIF_WIDTH_MINI;

        this._set_client_config();
        this.imgs_to_preload = this._init_image_html();
        this._init_video();
    };

    var MPNotif = MixpanelLib._Notification;

        MPNotif.ANIM_TIME         = 200;
        MPNotif.MARKUP_PREFIX     = 'mixpanel-notification';
        MPNotif.BG_OPACITY        = 0.6;
        MPNotif.NOTIF_TOP         = 25;
        MPNotif.NOTIF_START_TOP   = 200;
        MPNotif.NOTIF_WIDTH       = 388;
        MPNotif.NOTIF_WIDTH_MINI  = 420;
        MPNotif.NOTIF_HEIGHT_MINI = 85;
        MPNotif.THUMB_BORDER_SIZE = 5;
        MPNotif.THUMB_IMG_SIZE    = 60;
        MPNotif.THUMB_OFFSET      = Math.round(MPNotif.THUMB_IMG_SIZE / 2);
        MPNotif.VIDEO_WIDTH       = 595;
        MPNotif.VIDEO_HEIGHT      = 334;

        MPNotif.prototype.show = function() {
            var self = this;
            this._set_client_config();

            // don't display until HTML body exists
            if (!this.body_el) {
                setTimeout(function() { self.show(); }, 300);
                return;
            }

            this._init_styles();
            this._init_notification_el();

            // wait for any images to load before showing notification
            this._preload_images(this._attach_and_animate);
        };

        MPNotif.prototype.dismiss = _.safewrap(function() {
            var exiting_el = this.showing_video ? this._get_el('video') : this._get_notification_display_el();
            if (this.use_transitions) {
                this._remove_class('bg', 'visible');
                this._add_class(exiting_el, 'exiting');
                setTimeout(this._remove_notification_el, MPNotif.ANIM_TIME);
            } else {
                var notif_attr, notif_start, notif_goal;
                if (this.mini) {
                    notif_attr  = 'right';
                    notif_start = 20;
                    notif_goal  = -100;
                } else {
                    notif_attr  = 'top';
                    notif_start = MPNotif.NOTIF_TOP;
                    notif_goal  = MPNotif.NOTIF_START_TOP + MPNotif.NOTIF_TOP;
                }
                this._animate_els([
                    {
                        el:    this._get_el('bg'),
                        attr:  'opacity',
                        start: MPNotif.BG_OPACITY,
                        goal:  0.0
                    },
                    {
                        el:    exiting_el,
                        attr:  'opacity',
                        start: 1.0,
                        goal:  0.0
                    },
                    {
                        el:    exiting_el,
                        attr:  notif_attr,
                        start: notif_start,
                        goal:  notif_goal
                    }
                ], MPNotif.ANIM_TIME, this._remove_notification_el);
            }
        });

        MPNotif.prototype._add_class = _.safewrap(function(el, class_name) {
            class_name = MPNotif.MARKUP_PREFIX + '-' + class_name;
            if (typeof el === 'string') {
                el = this._get_el(el);
            }
            if (!el.className) {
                el.className = class_name;
            } else if (!~(' ' + el.className + ' ').indexOf(' ' + class_name + ' ')) {
                el.className += ' ' + class_name;
            }
        });
        MPNotif.prototype._remove_class = _.safewrap(function(el, class_name) {
            class_name = MPNotif.MARKUP_PREFIX + '-' + class_name;
            if (typeof el === 'string') {
                el = this._get_el(el);
            }
            if (el.className) {
                el.className = (' ' + el.className + ' ')
                    .replace(' ' + class_name + ' ', '')
                    .replace(/^[\s\xA0]+/, '')
                    .replace(/[\s\xA0]+$/, '');
            }
        });

        MPNotif.prototype._animate_els = _.safewrap(function(anims, mss, done_cb, start_time) {
            var self = this,
                in_progress = false,
                ai, anim,
                cur_time = 1 * new Date(), time_diff;

            start_time = start_time || cur_time;
            time_diff = cur_time - start_time;

            for (ai = 0; ai < anims.length; ai++) {
                anim = anims[ai];
                if (typeof anim.val === 'undefined') {
                    anim.val = anim.start;
                }
                if (anim.val !== anim.goal) {
                    in_progress = true;
                    var anim_diff = anim.goal - anim.start,
                        anim_dir = anim.goal >= anim.start ? 1 : -1;
                    anim.val = anim.start + anim_diff * time_diff / mss;
                    if (anim.attr !== 'opacity') {
                        anim.val = Math.round(anim.val);
                    }
                    if ((anim_dir > 0 && anim.val >= anim.goal) || (anim_dir < 0 && anim.val <= anim.goal)) {
                        anim.val = anim.goal;
                    }
                }
            }
            if (!in_progress) {
                if (done_cb) {
                    done_cb();
                }
                return;
            }

            for (ai = 0; ai < anims.length; ai++) {
                anim = anims[ai];
                if (anim.el) {
                    var suffix = anim.attr === 'opacity' ? '' : 'px';
                    anim.el.style[anim.attr] = String(anim.val) + suffix;
                }
            }
            setTimeout(function() { self._animate_els(anims, mss, done_cb, start_time); }, 10);
        });

        MPNotif.prototype._attach_and_animate = _.safewrap(function() {
            var self = this;

            // no possibility to double-display
            if (this.shown || this._get_shown_campaigns()[this.campaign_id]) {
                return;
            }
            this.shown = true;

            this.body_el.appendChild(this.notification_el);
            setTimeout(function() {
                var notif_el = self._get_notification_display_el();
                if (self.use_transitions) {
                    if (!self.mini) {
                        self._add_class('bg', 'visible');
                    }
                    self._add_class(notif_el, 'visible');
                    self._mark_as_shown();
                } else {
                    var notif_attr, notif_start, notif_goal;
                    if (self.mini) {
                        notif_attr  = 'right';
                        notif_start = -100;
                        notif_goal  = 20;
                    } else {
                        notif_attr  = 'top';
                        notif_start = MPNotif.NOTIF_START_TOP + MPNotif.NOTIF_TOP;
                        notif_goal  = MPNotif.NOTIF_TOP;
                    }
                    self._animate_els([
                        {
                            el:    self._get_el('bg'),
                            attr:  'opacity',
                            start: 0.0,
                            goal:  MPNotif.BG_OPACITY
                        },
                        {
                            el:    notif_el,
                            attr:  'opacity',
                            start: 0.0,
                            goal:  1.0
                        },
                        {
                            el:    notif_el,
                            attr:  notif_attr,
                            start: notif_start,
                            goal:  notif_goal
                        }
                    ], MPNotif.ANIM_TIME, self._mark_as_shown);
                }
            }, 100);
            _.register_event(self._get_el('cancel'), 'click', function(e) {
                e.preventDefault();
                self.dismiss();
            });
            var click_el = self._get_el('button') ||
                           self._get_el('mini-content');
            _.register_event(click_el, 'click', function(e) {
                e.preventDefault();
                if (self.show_video) {
                    self._track_event('$campaign_open', {'$resource_type': 'video'});
                    self._switch_to_video();
                } else {
                    self.dismiss();
                    if (self.clickthrough) {
                        self._track_event('$campaign_open', {'$resource_type': 'link'}, function() {
                            window.location.href = self.dest_url;
                        });
                    }
                }
            });
        });

        MPNotif.prototype._get_el = function(id) {
            return document.getElementById(MPNotif.MARKUP_PREFIX + '-' + id);
        };

        MPNotif.prototype._get_notification_display_el = function() {
            return this._get_el(this.notif_type);
        };

        MPNotif.prototype._get_shown_campaigns = function() {
            return this.cookie['props'][CAMPAIGN_IDS_KEY] || (this.cookie['props'][CAMPAIGN_IDS_KEY] = {});
        };

        MPNotif.prototype._browser_lte = function(browser, version) {
            return this.browser_versions[browser] && this.browser_versions[browser] <= version;
        };

        MPNotif.prototype._init_image_html = function() {
            var imgs_to_preload = [];

            if (!this.mini) {
                if (this.image_url) {
                    imgs_to_preload.push(this.image_url);
                    this.img_html = '<img id="img" src="' + this.image_url + '"/>';
                } else {
                    this.img_html = '';
                }
                if (this.thumb_image_url) {
                    imgs_to_preload.push(this.thumb_image_url);
                    this.thumb_img_html =
                        '<div id="thumbborder-wrapper"><div id="thumbborder"></div></div>' +
                        '<img id="thumbnail"' +
                            ' src="' + this.thumb_image_url + '"' +
                            ' width="' + MPNotif.THUMB_IMG_SIZE + '"' +
                            ' height="' + MPNotif.THUMB_IMG_SIZE + '"' +
                        '/>' +
                        '<div id="thumbspacer"></div>';
                } else {
                    this.thumb_img_html = '';
                }
            } else {
                this.thumb_image_url = this.thumb_image_url || '//cdn.mxpnl.com/site_media/images/icons/notifications/mini-news-dark.png';
                imgs_to_preload.push(this.thumb_image_url);
            }

            return imgs_to_preload;
        };

        MPNotif.prototype._init_notification_el = function() {
            var notification_html = '',
                video_src         = '',
                video_html        = '',
                cancel_html       = '<div id="cancel">' +
                                        '<div id="cancel-icon"></div>' +
                                    '</div>';

            this.notification_el = document.createElement('div');
            this.notification_el.id = MPNotif.MARKUP_PREFIX + '-wrapper';
            if (!this.mini) {
                // TAKEOVER notification
                var close_html  = (this.clickthrough || this.show_video) ? '' : '<div id="button-close"></div>',
                    play_html   = this.show_video ? '<div id="button-play"></div>' : '';
                if (this._browser_lte('ie', 7)) {
                    close_html = '';
                    play_html = '';
                }
                notification_html =
                    '<div id="takeover">' +
                        this.thumb_img_html +
                        '<div id="mainbox">' +
                            cancel_html +
                            '<div id="content">' +
                                this.img_html +
                                '<div id="title">' + this.title + '</div>' +
                                '<div id="body">' + this.body + '</div>' +
                                '<div id="tagline">' +
                                    '<a href="http://mixpanel.com?from=inapp" target="_blank">POWERED BY MIXPANEL</a>' +
                                '</div>' +
                            '</div>' +
                            '<div id="button">' +
                                close_html +
                                '<a id="button-link" href="' + this.dest_url + '">' + this.cta + '</a>' +
                                play_html +
                            '</div>' +
                        '</div>' +
                    '</div>';
            } else {
                // MINI notification
                notification_html =
                    '<div id="mini">' +
                        '<div id="mainbox">' +
                            cancel_html +
                            '<div id="mini-content">' +
                                '<div id="mini-icon">' +
                                    '<div id="mini-icon-img"></div>' +
                                '</div>' +
                                '<div id="body">' +
                                    '<div id="body-text"><div>' + this.body + '</div></div>' +
                                '</div>' +
                            '</div>' +
                        '</div>' +
                        '<div id="mini-border"></div>' +
                    '</div>';
            }
            if (this.youtube_video) {
                video_src = '//www.youtube.com/embed/' + this.youtube_video +
                    '?wmode=transparent&showinfo=0&modestbranding=0&rel=0&autoplay=1&loop=0&vq=hd1080';
                if (this.yt_custom) {
                    video_src += '&enablejsapi=1&html5=1&controls=0';
                    video_html =
                        '<div id="video-controls">' +
                            '<div id="video-progress" class="video-progress-el">' +
                                '<div id="video-progress-total" class="video-progress-el"></div>' +
                                '<div id="video-elapsed" class="video-progress-el"></div>' +
                            '</div>' +
                            '<div id="video-time" class="video-progress-el"></div>' +
                        '</div>';
                }
            } else if (this.vimeo_video) {
                video_src = '//player.vimeo.com/video/' + this.vimeo_video + '?autoplay=1&title=0&byline=0&portrait=0';
            }
            if (this.show_video) {
                this.video_iframe =
                    '<iframe id="' + MPNotif.MARKUP_PREFIX + '-video-frame" ' +
                        'width="' + this.video_width + '" height="' + this.video_height + '" ' +
                        ' src="' + video_src + '"' +
                        ' frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen="1" scrolling="no"' +
                    '></iframe>';
                video_html =
                    '<div id="video-' + (this.flip_animate ? '' : 'no') + 'flip">' +
                        '<div id="video">' +
                            '<div id="video-holder"></div>' +
                            video_html +
                        '</div>' +
                    '</div>';
            }
            var main_html = video_html + notification_html;
            if (this.flip_animate) {
                main_html =
                    (this.mini ? notification_html : '') +
                    '<div id="flipcontainer"><div id="flipper">' +
                        (this.mini ? video_html : main_html) +
                    '</div></div>';
            }

            this.notification_el.innerHTML =
                ('<div id="overlay" class="' + this.notif_type + '">' +
                    '<div id="campaignid-' + this.campaign_id + '">' +
                        '<div id="bgwrapper">' +
                            '<div id="bg"></div>' +
                            main_html +
                        '</div>' +
                    '</div>' +
                '</div>')
                .replace(/class=\"/g, 'class="' + MPNotif.MARKUP_PREFIX + '-')
                .replace(/id=\"/g, 'id="' + MPNotif.MARKUP_PREFIX + '-');
        };

        MPNotif.prototype._init_styles = function() {
            if (this.style === 'dark') {
                this.style_vals = {
                    bg:             '#1d1f25',
                    bg_actions:     '#282b32',
                    bg_hover:       '#3a4147',
                    bg_light:       '#4a5157',
                    border_gray:    '#32353c',
                    cancel_opacity: '0.4',
                    mini_hover:     '#2a3137',
                    text_title:     '#fff',
                    text_main:      '#9498a3',
                    text_tagline:   '#464851',
                    text_hover:     '#ddd'
                };
            } else {
                this.style_vals = {
                    bg:             '#fff',
                    bg_actions:     '#e7eaee',
                    bg_hover:       '#eceff3',
                    bg_light:       '#f5f5f5',
                    border_gray:    '#e4ecf2',
                    cancel_opacity: '1.0',
                    mini_hover:     '#fafafa',
                    text_title:     '#5c6578',
                    text_main:      '#8b949b',
                    text_tagline:   '#ced9e6',
                    text_hover:     '#7c8598'
                };
            }
            var shadow = '0px 0px 35px 0px rgba(45, 49, 56, 0.7)',
                video_shadow = shadow,
                mini_shadow = shadow,
                thumb_total_size = MPNotif.THUMB_IMG_SIZE + MPNotif.THUMB_BORDER_SIZE * 2,
                anim_seconds = (MPNotif.ANIM_TIME / 1000) + 's';
            if (this.mini) {
                shadow = 'none';
            }

            // don't display on small viewports
            var notif_media_queries = {},
                min_width = MPNotif.NOTIF_WIDTH_MINI + 20;
            notif_media_queries['@media only screen and (max-width: ' + (min_width - 1) + 'px)'] = {
                '#overlay': {
                    'display': 'none'
                }
            };
            var notif_styles = {
                '.flipped': {
                    'transform': 'rotateY(180deg)'
                },
                '#overlay': {
                    'position': 'fixed',
                    'top': '0',
                    'left': '0',
                    'width': '100%',
                    'height': '100%',
                    'overflow': 'auto',
                    'text-align': 'center',
                    'z-index': '10000',
                    'font-family': '"Helvetica", "Arial", sans-serif',
                    '-webkit-font-smoothing': 'antialiased',
                    '-moz-osx-font-smoothing': 'grayscale'
                },
                    '#overlay.mini': {
                        'height': '0',
                        'overflow': 'visible'
                    },
                '#overlay a': {
                    'width': 'initial',
                    'padding': '0',
                    'text-decoration': 'none',
                    'text-transform': 'none',
                    'color': 'inherit'
                },
                '#bgwrapper': {
                    'position': 'relative',
                    'width': '100%',
                    'height': '100%'
                },
                '#bg': {
                    'position': 'fixed',
                    'top': '0',
                    'left': '0',
                    'width': '100%',
                    'height': '100%',
                    'min-width': this.doc_width * 4 + 'px',
                    'min-height': this.doc_height * 4 + 'px',
                    'background-color': 'black',
                    'opacity': '0.0',
                    '-ms-filter': 'progid:DXImageTransform.Microsoft.Alpha(Opacity=60)', // IE8
                    'filter': 'alpha(opacity=60)', // IE5-7
                    'transition': 'opacity ' + anim_seconds
                },
                    '#bg.visible': {
                        'opacity': MPNotif.BG_OPACITY
                    },
                    '.mini #bg': {
                        'width': '0',
                        'height': '0',
                        'min-width': '0'
                    },
                '#flipcontainer': {
                    'perspective': '1000px',
                    'position': 'absolute',
                    'width': '100%'
                },
                '#flipper': {
                    'position': 'relative',
                    'transform-style': 'preserve-3d',
                    'transition': '0.3s'
                },
                '#takeover': {
                    'position': 'absolute',
                    'left': '50%',
                    'width': MPNotif.NOTIF_WIDTH + 'px',
                    'margin-left': Math.round(-MPNotif.NOTIF_WIDTH / 2) + 'px',
                    'backface-visibility': 'hidden',
                    'transform': 'rotateY(0deg)',
                    'opacity': '0.0',
                    'top': MPNotif.NOTIF_START_TOP + 'px',
                    'transition': 'opacity ' + anim_seconds + ', top ' + anim_seconds
                 },
                    '#takeover.visible': {
                        'opacity': '1.0',
                        'top': MPNotif.NOTIF_TOP + 'px'
                    },
                    '#takeover.exiting': {
                        'opacity': '0.0',
                        'top': MPNotif.NOTIF_START_TOP + 'px'
                    },
                '#thumbspacer': {
                    'height': MPNotif.THUMB_OFFSET + 'px'
                },
                '#thumbborder-wrapper': {
                    'position': 'absolute',
                    'top': (-MPNotif.THUMB_BORDER_SIZE) + 'px',
                    'left': (MPNotif.NOTIF_WIDTH / 2 - MPNotif.THUMB_OFFSET - MPNotif.THUMB_BORDER_SIZE) + 'px',
                    'width': thumb_total_size + 'px',
                    'height': (thumb_total_size / 2) + 'px',
                    'overflow': 'hidden'
                },
                '#thumbborder': {
                    'position': 'absolute',
                    'width': thumb_total_size + 'px',
                    'height': thumb_total_size + 'px',
                    'border-radius': thumb_total_size + 'px',
                    'background-color': this.style_vals.bg_actions,
                    'opacity': '0.5'
                },
                '#thumbnail': {
                    'position': 'absolute',
                    'top': '0px',
                    'left': (MPNotif.NOTIF_WIDTH / 2 - MPNotif.THUMB_OFFSET) + 'px',
                    'width': MPNotif.THUMB_IMG_SIZE + 'px',
                    'height': MPNotif.THUMB_IMG_SIZE + 'px',
                    'overflow': 'hidden',
                    'z-index': '100',
                    'border-radius': MPNotif.THUMB_IMG_SIZE + 'px'
                },
                '#mini': {
                    'position': 'absolute',
                    'right': '20px',
                    'top': MPNotif.NOTIF_TOP + 'px',
                    'width': this.notif_width + 'px',
                    'height': MPNotif.NOTIF_HEIGHT_MINI * 2 + 'px',
                    'margin-top': 20 - MPNotif.NOTIF_HEIGHT_MINI + 'px',
                    'backface-visibility': 'hidden',
                    'opacity': '0.0',
                    'transform': 'rotateX(90deg)',
                    'transition': 'opacity 0.3s, transform 0.3s, right 0.3s'
                },
                    '#mini.visible': {
                        'opacity': '1.0',
                        'transform': 'rotateX(0deg)'
                    },
                    '#mini.exiting': {
                        'opacity': '0.0',
                        'right': '-150px'
                    },
                '#mainbox': {
                    'border-radius': '4px',
                    'box-shadow': shadow,
                    'text-align': 'center',
                    'background-color': this.style_vals.bg,
                    'font-size': '14px',
                    'color': this.style_vals.text_main
                },
                    '#mini #mainbox': {
                        'height': MPNotif.NOTIF_HEIGHT_MINI + 'px',
                        'margin-top': MPNotif.NOTIF_HEIGHT_MINI + 'px',
                        'border-radius': '3px',
                        'transition': 'background-color ' + anim_seconds
                    },
                '#mini-border': {
                    'height': (MPNotif.NOTIF_HEIGHT_MINI + 6) + 'px',
                    'width': (MPNotif.NOTIF_WIDTH_MINI + 6) + 'px',
                    'position': 'absolute',
                    'top': '-3px',
                    'left': '-3px',
                    'margin-top': MPNotif.NOTIF_HEIGHT_MINI + 'px',
                    'border-radius': '6px',
                    'opacity': '0.25',
                    'background-color': '#fff',
                    'z-index': '-1',
                    'box-shadow': mini_shadow
                },
                '#mini-icon': {
                    'position': 'relative',
                    'display': 'inline-block',
                    'width': '75px',
                    'height': MPNotif.NOTIF_HEIGHT_MINI + 'px',
                    'border-radius': '3px 0 0 3px',
                    'background-color': this.style_vals.bg_actions,
                    'background': 'linear-gradient(135deg, ' + this.style_vals.bg_light + ' 0%, ' + this.style_vals.bg_actions + ' 100%)',
                    'transition': 'background-color ' + anim_seconds
                },
                '#mini:hover #mini-icon': {
                    'background-color': this.style_vals.mini_hover
                },
                '#mini:hover #mainbox': {
                    'background-color': this.style_vals.mini_hover
                },
                '#mini-icon-img': {
                    'position': 'absolute',
                    'background-image': 'url(' + this.thumb_image_url + ')',
                    'width': '48px',
                    'height': '48px',
                    'top': '20px',
                    'left': '12px'
                },
                '#content': {
                    'padding': '30px 20px 0px 20px'
                },
                '#mini-content': {
                    'text-align': 'left',
                    'height': MPNotif.NOTIF_HEIGHT_MINI + 'px',
                    'cursor': 'pointer'
                },
                '#img': {
                    'width': '328px',
                    'margin-top': '30px',
                    'border-radius': '5px'
                },
                '#title': {
                    'max-height': '600px',
                    'overflow': 'hidden',
                    'word-wrap': 'break-word',
                    'padding': '25px 0px 20px 0px',
                    'font-size': '19px',
                    'font-weight': 'bold',
                    'color': this.style_vals.text_title
                },
                '#body': {
                    'max-height': '600px',
                    'margin-bottom': '25px',
                    'overflow': 'hidden',
                    'word-wrap': 'break-word',
                    'line-height': '21px',
                    'font-size': '15px',
                    'font-weight': 'normal',
                    'text-align': 'left'
                },
                    '#mini #body': {
                        'display': 'inline-block',
                        'max-width': '250px',
                        'margin': '0 0 0 30px',
                        'height': MPNotif.NOTIF_HEIGHT_MINI + 'px',
                        'font-size': '16px',
                        'letter-spacing': '0.8px',
                        'color': this.style_vals.text_title
                    },
                    '#mini #body-text': {
                        'display': 'table',
                        'height': MPNotif.NOTIF_HEIGHT_MINI + 'px'
                    },
                    '#mini #body-text div': {
                        'display': 'table-cell',
                        'vertical-align': 'middle'
                    },
                '#tagline': {
                    'margin-bottom': '15px',
                    'font-size': '10px',
                    'font-weight': '600',
                    'letter-spacing': '0.8px',
                    'color': '#ccd7e0',
                    'text-align': 'left'
                },
                '#tagline a': {
                    'color': this.style_vals.text_tagline,
                    'transition': 'color ' + anim_seconds
                },
                '#tagline a:hover': {
                    'color': this.style_vals.text_hover
                },
                '#cancel': {
                    'position': 'absolute',
                    'right': '0',
                    'width': '8px',
                    'height': '8px',
                    'padding': '10px',
                    'border-radius': '20px',
                    'margin': '12px 12px 0 0',
                    'box-sizing': 'content-box',
                    'cursor': 'pointer',
                    'transition': 'background-color ' + anim_seconds
                },
                    '#mini #cancel': {
                        'margin': '7px 7px 0 0'
                    },
                '#cancel-icon': {
                    'width': '8px',
                    'height': '8px',
                    'overflow': 'hidden',
                    'background-image': 'url(//cdn.mxpnl.com/site_media/images/icons/notifications/cancel-x.png)',
                    'opacity': this.style_vals.cancel_opacity
                },
                '#cancel:hover': {
                    'background-color': this.style_vals.bg_hover
                },
                '#button': {
                    'display': 'block',
                    'height': '60px',
                    'line-height': '60px',
                    'text-align': 'center',
                    'background-color': this.style_vals.bg_actions,
                    'border-radius': '0 0 4px 4px',
                    'overflow': 'hidden',
                    'cursor': 'pointer',
                    'transition': 'background-color ' + anim_seconds
                },
                '#button-close': {
                    'display': 'inline-block',
                    'width': '9px',
                    'height': '60px',
                    'margin-right': '8px',
                    'vertical-align': 'top',
                    'background-image': 'url(//cdn.mxpnl.com/site_media/images/icons/notifications/close-x-' + this.style + '.png)',
                    'background-repeat': 'no-repeat',
                    'background-position': '0px 25px'
                },
                '#button-play': {
                    'display': 'inline-block',
                    'width': '30px',
                    'height': '60px',
                    'margin-left': '15px',
                    'background-image': 'url(//cdn.mxpnl.com/site_media/images/icons/notifications/play-' + this.style + '-small.png)',
                    'background-repeat': 'no-repeat',
                    'background-position': '0px 15px'
                },
                'a#button-link': {
                    'display': 'inline-block',
                    'vertical-align': 'top',
                    'text-align': 'center',
                    'font-size': '17px',
                    'font-weight': 'bold',
                    'overflow': 'hidden',
                    'word-wrap': 'break-word',
                    'color': this.style_vals.text_title,
                    'transition': 'color ' + anim_seconds
                },
                '#button:hover': {
                    'background-color': this.style_vals.bg_hover,
                    'color': this.style_vals.text_hover
                },
                '#button:hover a': {
                    'color': this.style_vals.text_hover
                },

                '#video-noflip': {
                    'position': 'relative',
                    'top': (-this.video_height * 2) + 'px'
                },
                '#video-flip': {
                    'backface-visibility': 'hidden',
                    'transform': 'rotateY(180deg)'
                },
                '#video': {
                    'position': 'absolute',
                    'width': (this.video_width - 1) + 'px',
                    'height': this.video_height + 'px',
                    'top': MPNotif.NOTIF_TOP + 'px',
                    'margin-top': '100px',
                    'left': '50%',
                    'margin-left': Math.round(-this.video_width / 2) + 'px',
                    'overflow': 'hidden',
                    'border-radius': '5px',
                    'box-shadow': video_shadow,
                    'transform': 'translateZ(1px)', // webkit rendering bug http://stackoverflow.com/questions/18167981/clickable-link-area-unexpectedly-smaller-after-css-transform
                    'transition': 'opacity ' + anim_seconds + ', top ' + anim_seconds
                },
                    '#video.exiting': {
                        'opacity': '0.0',
                        'top': this.video_height + 'px'
                    },
                '#video-holder': {
                    'position': 'absolute',
                    'width': (this.video_width - 1) + 'px',
                    'height': this.video_height + 'px',
                    'overflow': 'hidden',
                    'border-radius': '5px'
                },
                '#video-frame': {
                    'margin-left': '-1px',
                    'width': this.video_width + 'px'
                },
                '#video-controls': {
                    'opacity': '0',
                    'transition': 'opacity 0.5s'
                },
                '#video:hover #video-controls': {
                    'opacity': '1.0'
                },
                '#video .video-progress-el': {
                    'position': 'absolute',
                    'bottom': '0',
                    'height': '25px',
                    'border-radius': '0 0 0 5px'
                },
                '#video-progress': {
                    'width': '90%'
                },
                '#video-progress-total': {
                    'width': '100%',
                    'background-color': this.style_vals.bg,
                    'opacity': '0.7'
                },
                '#video-elapsed': {
                    'width': '0',
                    'background-color': '#6cb6f5',
                    'opacity': '0.9'
                },
                '#video #video-time': {
                    'width': '10%',
                    'right': '0',
                    'font-size': '11px',
                    'line-height': '25px',
                    'color': this.style_vals.text_main,
                    'background-color': '#666',
                    'border-radius': '0 0 5px 0'
                }
            };

            // IE hacks
            if (this._browser_lte('ie', 8)) {
                _.extend(notif_styles, {
                    '* html #overlay': {
                        'position': 'absolute'
                    },
                    '* html #bg': {
                        'position': 'absolute'
                    },
                    'html, body': {
                        'height': '100%'
                    }
                });
            }
            if (this._browser_lte('ie', 7)) {
                _.extend(notif_styles, {
                    '#mini #body': {
                        'display': 'inline',
                        'zoom': '1',
                        'border': '1px solid ' + this.style_vals.bg_hover
                    },
                    '#mini #body-text': {
                        'padding': '20px'
                    },
                    '#mini #mini-icon': {
                        'display': 'none'
                    }
                });
            }

            // add vendor-prefixed style rules
            var VENDOR_STYLES   = ['backface-visibility', 'border-radius', 'box-shadow', 'opacity',
                                   'perspective', 'transform', 'transform-style', 'transition'],
                VENDOR_PREFIXES = ['khtml', 'moz', 'ms', 'o', 'webkit'];
            for (var selector in notif_styles) {
                for (var si = 0; si < VENDOR_STYLES.length; si++) {
                    var prop = VENDOR_STYLES[si];
                    if (prop in notif_styles[selector]) {
                        var val = notif_styles[selector][prop];
                        for (var pi = 0; pi < VENDOR_PREFIXES.length; pi++) {
                            notif_styles[selector]['-' + VENDOR_PREFIXES[pi] + '-' + prop] = val;
                        }
                    }
                }
            }

            var inject_styles = function(styles, media_queries) {
                var create_style_text = function(style_defs) {
                    var st = '';
                    for (var selector in style_defs) {
                        var mp_selector = selector
                            .replace(/#/g, '#' + MPNotif.MARKUP_PREFIX + '-')
                            .replace(/\./g, '.' + MPNotif.MARKUP_PREFIX + '-');
                        st += '\n' + mp_selector + ' {';
                        var props = style_defs[selector];
                        for (var k in props) {
                            st += k + ':' + props[k] + ';';
                        }
                        st += '}';
                    }
                    return st;
                };
                var create_media_query_text = function(mq_defs) {
                    var mqt = '';
                    for (var mq in mq_defs) {
                        mqt += '\n' + mq + ' {' + create_style_text(mq_defs[mq]) + '\n}';
                    }
                    return mqt;
                }

                var style_text = create_style_text(styles) + create_media_query_text(media_queries),
                    head_el = document.head || document.getElementsByTagName('head')[0] || document.documentElement,
                    style_el = document.createElement('style');
                head_el.appendChild(style_el);
                style_el.setAttribute('type', 'text/css');
                if (style_el.styleSheet) { // IE
                    style_el.styleSheet.cssText = style_text;
                } else {
                    style_el.textContent = style_text;
                }
            };
            inject_styles(notif_styles, notif_media_queries);
        };

        MPNotif.prototype._init_video = _.safewrap(function() {
            if (!this.video_url) {
                return;
            }
            var self = this;

            // Youtube iframe API compatibility
            self.yt_custom = 'postMessage' in window;

            // detect CSS compatibility
            var sample_styles = document.createElement('div').style,
                is_css_compatible = function(rule) {
                    if (rule in sample_styles) {
                        return true;
                    }
                    rule = rule[0].toUpperCase() + rule.slice(1);
                    var props = ['O' + rule, 'ms' + rule, 'Webkit' + rule, 'Moz' + rule];
                    for (var i = 0; i < props.length; i++) {
                        if (props[i] in sample_styles) {
                            return true;
                        }
                    }
                    return false;
                };

            self.dest_url = self.video_url;
            var youtube_match = self.video_url.match(
                    // http://stackoverflow.com/questions/2936467/parse-youtube-video-id-using-preg-match
                    /(?:youtube(?:-nocookie)?\.com\/(?:[^\/]+\/.+\/|(?:v|e(?:mbed)?)\/|.*[?&]v=)|youtu\.be\/)([^"&?\/ ]{11})/i
                ),
                vimeo_match = self.video_url.match(
                    /vimeo\.com\/.*?(\d+)/i
                );
            if (youtube_match) {
                self.show_video = true;
                self.youtube_video = youtube_match[1];

                if (self.yt_custom) {
                    window['onYouTubeIframeAPIReady'] = function() {
                        if (self._get_el('video-frame')) {
                            self._yt_video_ready();
                        }
                    };

                    // load Youtube iframe API; see https://developers.google.com/youtube/iframe_api_reference
                    var tag = document.createElement('script');
                    tag.src = "//www.youtube.com/iframe_api";
                    var firstScriptTag = document.getElementsByTagName('script')[0];
                    firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);
                }
            } else if (vimeo_match) {
                self.show_video = true;
                self.vimeo_video = vimeo_match[1];
            }

            // IE <= 7, FF <= 3: fall through to video link rather than embedded player
            if (self._browser_lte('ie', 7) || self._browser_lte('firefox', 3)) {
                self.show_video = false;
                self.clickthrough = true;
            }
        });

        MPNotif.prototype._mark_as_shown = _.safewrap(function() {
            // click on background to dismiss
            var self = this;
            _.register_event(self._get_el('bg'), 'click', function(e) {
                self.dismiss();
            });

            var get_style = function(el, style_name) {
                var styles = {};
                if (document.defaultView && document.defaultView.getComputedStyle) {
                    styles = document.defaultView.getComputedStyle(el, null); // FF3 requires both args
                } else if (el.currentStyle) { // IE
                    styles = el.currentStyle;
                }
                return styles[style_name];
            };

            if (this.campaign_id) {
                var notif_el = this._get_el('overlay');
                if (notif_el && get_style(notif_el, 'visibility') !== 'hidden' && get_style(notif_el, 'display') !== 'none') {
                    // mark notification shown (local cache)
                    this._get_shown_campaigns()[this.campaign_id] = 1 * new Date();
                    this.cookie.save();

                    // track delivery
                    this._track_event('$campaign_delivery');

                    // mark notification shown (mixpanel property)
                    this.mixpanel['people']['append']({
                        '$campaigns': this.campaign_id,
                        '$notifications': {
                            'campaign_id': this.campaign_id,
                            'message_id':  this.message_id,
                            'type':        'web',
                            'time':        new Date()
                        }
                    });
                }
            }
        });

        MPNotif.prototype._preload_images = function(all_loaded_cb) {
            var self = this;
            if (this.imgs_to_preload.length === 0) {
                all_loaded_cb();
                return;
            }

            var preloaded_imgs = 0,
                img_objs = [];
            for (var i = 0; i < this.imgs_to_preload.length; i++) {
                var img = new Image(),
                    onload = function() {
                        preloaded_imgs++;
                        if (preloaded_imgs === self.imgs_to_preload.length && all_loaded_cb) {
                            all_loaded_cb();
                            all_loaded_cb = null;
                        }
                    };
                img.onload = onload;
                img.src = this.imgs_to_preload[i];
                if (img.complete) {
                    onload();
                }
                img_objs.push(img);
            }

            // IE6/7 doesn't fire onload reliably
            if (this._browser_lte('ie', 7)) {
                setTimeout(function() {
                    var imgs_loaded = true;
                    for (i = 0; i < img_objs.length; i++) {
                        if (!img_objs[i].complete) {
                            imgs_loaded = false;
                        }
                    }
                    if (imgs_loaded && all_loaded_cb) {
                        all_loaded_cb();
                        all_loaded_cb = null;
                    }
                }, 500);
            }
        };

        MPNotif.prototype._remove_notification_el = _.safewrap(function() {
            window.clearInterval(this._video_progress_checker);
            this.notification_el.style.visibility = 'hidden';
            this.body_el.removeChild(this.notification_el);
        });

        MPNotif.prototype._set_client_config = function() {
            var get_browser_version = function(browser_ex) {
                var match = navigator.userAgent.match(browser_ex);
                return match && match[1];
            };
            this.browser_versions = {};
            this.browser_versions['chrome']  = get_browser_version(/Chrome\/(\d+)/);
            this.browser_versions['firefox'] = get_browser_version(/Firefox\/(\d+)/);
            this.browser_versions['ie']      = get_browser_version(/MSIE (\d+).+/);
            if (!this.browser_versions['ie'] && !(window.ActiveXObject) && "ActiveXObject" in window) {
                this.browser_versions['ie'] = 11;
            }

            this.body_el = document.body || document.getElementsByTagName('body')[0];
            if (this.body_el) {
                this.doc_width = Math.max(
                    this.body_el.scrollWidth, document.documentElement.scrollWidth,
                    this.body_el.offsetWidth, document.documentElement.offsetWidth,
                    this.body_el.clientWidth, document.documentElement.clientWidth
                );
                this.doc_height = Math.max(
                    this.body_el.scrollHeight, document.documentElement.scrollHeight,
                    this.body_el.offsetHeight, document.documentElement.offsetHeight,
                    this.body_el.clientHeight, document.documentElement.clientHeight
                );
            }

            // detect CSS compatibility
            var ie_ver = this.browser_versions['ie'];
            var sample_styles = document.createElement('div').style,
                is_css_compatible = function(rule) {
                    if (rule in sample_styles) {
                        return true;
                    }
                    if (!ie_ver) {
                        rule = rule[0].toUpperCase() + rule.slice(1);
                        var props = ['O' + rule, 'Webkit' + rule, 'Moz' + rule];
                        for (var i = 0; i < props.length; i++) {
                            if (props[i] in sample_styles) {
                                return true;
                            }
                        }
                    }
                    return false;
                };
            this.use_transitions =
                this.body_el &&
                is_css_compatible('transition') &&
                is_css_compatible('transform');
            this.flip_animate =
                (this.browser_versions['chrome'] >= 33 || this.browser_versions['firefox'] >= 15) &&
                this.body_el &&
                is_css_compatible('backfaceVisibility') &&
                is_css_compatible('perspective') &&
                is_css_compatible('transform');
        };

        MPNotif.prototype._switch_to_video = _.safewrap(function() {
            var self = this,
                anims = [
                    {
                        el:    self._get_notification_display_el(),
                        attr:  'opacity',
                        start: 1.0,
                        goal:  0.0
                    },
                    {
                        el:    self._get_notification_display_el(),
                        attr:  'top',
                        start: MPNotif.NOTIF_TOP,
                        goal:  -500
                    },
                    {
                        el:    self._get_el('video-noflip'),
                        attr:  'opacity',
                        start: 0.0,
                        goal:  1.0
                    },
                    {
                        el:    self._get_el('video-noflip'),
                        attr:  'top',
                        start: -self.video_height * 2,
                        goal:  0
                    }
                ];

            if (self.mini) {
                var bg = self._get_el('bg'),
                    overlay = self._get_el('overlay');
                bg.style.width = '100%';
                bg.style.height = '100%';
                overlay.style.width = '100%';

                self._add_class(self._get_notification_display_el(), 'exiting');
                self._add_class(bg, 'visible');

                anims.push({
                    el:    self._get_el('bg'),
                    attr:  'opacity',
                    start: 0.0,
                    goal:  MPNotif.BG_OPACITY
                });
            }

            var video_el = self._get_el('video-holder');
            video_el.innerHTML = self.video_iframe;

            var video_ready = function() {
                if (window['YT'] && window['YT']['loaded']) {
                    self._yt_video_ready();
                }
                self.showing_video = true;
                self._get_notification_display_el().style.visibility = 'hidden';
            };
            if (self.flip_animate) {
                self._add_class('flipper', 'flipped');
                setTimeout(video_ready, MPNotif.ANIM_TIME);
            } else {
                self._animate_els(anims, MPNotif.ANIM_TIME, video_ready);
            }
        });

        MPNotif.prototype._track_event = function(event_name, properties, cb) {
            if (this.campaign_id) {
                properties = properties || {};
                properties = _.extend(properties, {
                    'campaign_id':     this.campaign_id,
                    'message_id':      this.message_id,
                    'message_type':    'web_inapp',
                    'message_subtype': this.notif_type
                });
                this.mixpanel['track'](event_name, properties, cb);
            } else {
                cb && cb.call();
            }
        };

        MPNotif.prototype._yt_video_ready = _.safewrap(function() {
            var self = this;
            if (self.video_inited) {
                return;
            }
            self.video_inited = true;

            var progress_bar  = self._get_el('video-elapsed'),
                progress_time = self._get_el('video-time'),
                progress_el   = self._get_el('video-progress');

            new window['YT']['Player'](MPNotif.MARKUP_PREFIX + '-video-frame', {
                'events': {
                    'onReady': function(event) {
                        var ytplayer = event['target'],
                            video_duration = ytplayer['getDuration'](),
                            pad = function(i) {
                                return ('00' + i).slice(-2);
                            },
                            update_video_time = function(current_time) {
                                var secs = Math.round(video_duration - current_time),
                                    mins = Math.floor(secs / 60),
                                    hours = Math.floor(mins / 60);
                                secs -= mins * 60;
                                mins -= hours * 60;
                                progress_time.innerHTML = '-' + (hours ? hours + ':' : '') + pad(mins) + ':' + pad(secs);
                            };
                        update_video_time(0);
                        self._video_progress_checker = window.setInterval(function() {
                            var current_time = ytplayer['getCurrentTime']();
                            progress_bar.style.width = (current_time / video_duration * 100) + '%';
                            update_video_time(current_time);
                        }, 250);
                        _.register_event(progress_el, 'click', function(e) {
                            var clickx = Math.max(0, e.pageX - progress_el.getBoundingClientRect().left);
                            ytplayer['seekTo'](video_duration * clickx / progress_el.clientWidth, true);
                        });
                    }
                }
            });
        });

    // EXPORTS (for closure compiler)

    // Underscore Exports
    _['toArray']         = _.toArray;
    _['isObject']        = _.isObject;
    _['JSONEncode']      = _.JSONEncode;
    _['JSONDecode']      = _.JSONDecode;
    _['isBlockedUA']     = _.isBlockedUA;
    _['isEmptyObject']   = _.isEmptyObject;
    _['info']            = _.info;
    _['info']['device']  = _.info.device;
    _['info']['browser'] = _.info.browser;

    // MixpanelLib Exports
    MixpanelLib.prototype['init']                            = MixpanelLib.prototype.init;
    MixpanelLib.prototype['disable']                         = MixpanelLib.prototype.disable;
    MixpanelLib.prototype['track']                           = MixpanelLib.prototype.track;
    MixpanelLib.prototype['track_links']                     = MixpanelLib.prototype.track_links;
    MixpanelLib.prototype['track_forms']                     = MixpanelLib.prototype.track_forms;
    MixpanelLib.prototype['track_pageview']                  = MixpanelLib.prototype.track_pageview;
    MixpanelLib.prototype['register']                        = MixpanelLib.prototype.register;
    MixpanelLib.prototype['register_once']                   = MixpanelLib.prototype.register_once;
    MixpanelLib.prototype['unregister']                      = MixpanelLib.prototype.unregister;
    MixpanelLib.prototype['identify']                        = MixpanelLib.prototype.identify;
    MixpanelLib.prototype['alias']                           = MixpanelLib.prototype.alias;
    MixpanelLib.prototype['name_tag']                        = MixpanelLib.prototype.name_tag;
    MixpanelLib.prototype['set_config']                      = MixpanelLib.prototype.set_config;
    MixpanelLib.prototype['get_config']                      = MixpanelLib.prototype.get_config;
    MixpanelLib.prototype['get_property']                    = MixpanelLib.prototype.get_property;
    MixpanelLib.prototype['get_distinct_id']                 = MixpanelLib.prototype.get_distinct_id;
    MixpanelLib.prototype['toString']                        = MixpanelLib.prototype.toString;
    MixpanelLib.prototype['_check_and_handle_notifications'] = MixpanelLib.prototype._check_and_handle_notifications;
    MixpanelLib.prototype['_show_notification']              = MixpanelLib.prototype._show_notification;

    // MixpanelCookie Exports
    MixpanelCookie.prototype['properties']            = MixpanelCookie.prototype.properties;
    MixpanelCookie.prototype['update_search_keyword'] = MixpanelCookie.prototype.update_search_keyword;
    MixpanelCookie.prototype['update_referrer_info']  = MixpanelCookie.prototype.update_referrer_info;
    MixpanelCookie.prototype['get_cross_subdomain']   = MixpanelCookie.prototype.get_cross_subdomain;
    MixpanelCookie.prototype['clear']                 = MixpanelCookie.prototype.clear;

    // MixpanelPeople Exports
    MixpanelPeople.prototype['set']           = MixpanelPeople.prototype.set;
    MixpanelPeople.prototype['set_once']      = MixpanelPeople.prototype.set_once;
    MixpanelPeople.prototype['increment']     = MixpanelPeople.prototype.increment;
    MixpanelPeople.prototype['append']        = MixpanelPeople.prototype.append;
    MixpanelPeople.prototype['track_charge']  = MixpanelPeople.prototype.track_charge;
    MixpanelPeople.prototype['clear_charges'] = MixpanelPeople.prototype.clear_charges;
    MixpanelPeople.prototype['delete_user']   = MixpanelPeople.prototype.delete_user;
    MixpanelPeople.prototype['toString']      = MixpanelPeople.prototype.toString;

    _.safewrap_class(MixpanelCookie, ['_expire_notification_campaigns']);
    _.safewrap_class(MixpanelLib,    ['identify', '_check_and_handle_notifications', '_show_notification']);

    // Initialization
    if (_.isUndefined(mixpanel)) {
        // mixpanel wasn't initialized properly, report error and quit
        console.critical("'mixpanel' object not initialized. Ensure you are using the latest version of the Mixpanel JS Library along with the snippet we provide.");
        return;
    }
    if (mixpanel['__loaded'] || (mixpanel['config'] && mixpanel['cookie'])) {
        // lib has already been loaded at least once; we don't want to override the global object this time so bomb early
        console.error("Mixpanel library has already been downloaded at least once.");
        return;
    }
    if (SNIPPET_VERSION < 1.1) {
        // mixpanel wasn't initialized properly, report error and quit
        console.critical("Version mismatch; please ensure you're using the latest version of the Mixpanel code snippet.");
        return;
    }

    // Load instances of the Mixpanel Library
    var instances = {};
    _.each(mixpanel['_i'], function(item) {
        var name, instance;
        if (item && _.isArray(item)) {
            name = item[item.length-1];
            instance = create_mplib.apply(this, item);

            instances[name] = instance;
        }
    });

    var extend_mp = function() {
        // add all the sub mixpanel instances
        _.each(instances, function(instance, name) {
            if (name !== PRIMARY_INSTANCE_NAME) { mixpanel[name] = instance; }
        });

        // add private functions as _
        mixpanel['_'] = _;
    };

    // we override the snippets init function to handle the case where a
    // user initializes the mixpanel library after the script loads & runs
    mixpanel['init'] = function(token, config, name) {
        if (name) {
            // initialize a sub library
            if (!mixpanel[name]) {
                mixpanel[name] = instances[name] = create_mplib(token, config, name);
                mixpanel[name]._loaded();
            }
        } else {
            var instance = mixpanel;

            if (instances[PRIMARY_INSTANCE_NAME]) {
                // main mixpanel lib already initialized
                instance = instances[PRIMARY_INSTANCE_NAME];
            } else if (token) {
                // intialize the main mixpanel lib
                instance = create_mplib(token, config, PRIMARY_INSTANCE_NAME);
                instance._loaded();
            }

            window[PRIMARY_INSTANCE_NAME] = mixpanel = instance;
            extend_mp();
        }
    };

    mixpanel['init']();

    // Fire loaded events after updating the window's mixpanel object
    _.each(instances, function(instance) {
        instance._loaded();
    });

    // Cross browser DOM Loaded support

    function dom_loaded_handler() {
        // function flag since we only want to execute this once
        if (dom_loaded_handler.done) { return; }
        dom_loaded_handler.done = true;

        DOM_LOADED = true;
        ENQUEUE_REQUESTS = false;

        _.each(instances, function(inst) {
            inst._dom_loaded();
        });
    }

    if (document.addEventListener) {
        if (document.readyState == "complete") {
            // safari 4 can fire the DOMContentLoaded event before loading all
            // external JS (including this file). you will see some copypasta
            // on the internet that checks for 'complete' and 'loaded', but
            // 'loaded' is an IE thing
            dom_loaded_handler();
        } else {
            document.addEventListener("DOMContentLoaded", dom_loaded_handler, false);
        }
    } else if (document.attachEvent) {
        // IE
        document.attachEvent("onreadystatechange", dom_loaded_handler);

        // check to make sure we arn't in a frame
        var toplevel = false;
        try {
            toplevel = window.frameElement == null;
        } catch(e) {}

        if (document.documentElement.doScroll && toplevel) {
            function do_scroll_check() {
                try {
                    document.documentElement.doScroll("left");
                } catch(e) {
                    setTimeout(do_scroll_check, 1);
                    return;
                }

                dom_loaded_handler();
            };

            do_scroll_check();
        }
    }

    // fallback handler, always will work
    _.register_event(window, 'load', dom_loaded_handler, true);

})(window['mixpanel']);