diff --git a/README.md b/README.md
index 9480032..8f9f424 100644
--- a/README.md
+++ b/README.md
@@ -27,11 +27,15 @@ var ncp = require('ncp').ncp;
 
 ncp.limit = 16;
 
-ncp(source, destination, function (err) {
+ncp(source, destination, (err) => {
+ //if the process have errors
  if (err) {
    return console.error(err);
  }
+ //no error | process successfully completed
+ else{
  console.log('done!');
+ }
 });
 ```
 
diff --git a/lib/ncp.js b/lib/ncp.js
index 96eed47..7f019bd 100644
--- a/lib/ncp.js
+++ b/lib/ncp.js
@@ -1,5 +1,5 @@
 var fs = require('fs'),
-    path = require('path');
+var path = require('path');
 
 module.exports = ncp;
 ncp.ncp = ncp;
@@ -31,7 +31,7 @@ function ncp (source, dest, options, callback) {
 
   startCopy(currentPath);
   
-  function startCopy(source) {
+   startCopy = (source) => {
     started++;
     if (filter) {
       if (filter instanceof RegExp) {
@@ -48,7 +48,7 @@ function ncp (source, dest, options, callback) {
     return getStats(source);
   }
 
-  function getStats(source) {
+   getStats = (source) => {
     var stat = dereference ? fs.stat : fs.lstat;
     if (running >= limit) {
       return setImmediate(function () {
@@ -81,7 +81,7 @@ function ncp (source, dest, options, callback) {
     });
   }
 
-  function onFile(file) {
+  onFile = (file) => {
     var target = file.name.replace(currentPath, targetPath);
     if(rename) {
       target =  rename(target);
@@ -110,7 +110,7 @@ function ncp (source, dest, options, callback) {
     });
   }
 
-  function copyFile(file, target) {
+   copyFile = (file, target)=> {
     var readStream = fs.createReadStream(file.name),
         writeStream = fs.createWriteStream(target, { mode: file.mode });
     
@@ -134,7 +134,7 @@ function ncp (source, dest, options, callback) {
     });
   }
 
-  function rmFile(file, done) {
+  rmFile = (file, done) => {
     fs.unlink(file, function (err) {
       if (err) {
         return onError(err);
@@ -143,7 +143,7 @@ function ncp (source, dest, options, callback) {
     });
   }
 
-  function onDir(dir) {
+   onDir = (dir) => {
     var target = dir.name.replace(currentPath, targetPath);
     isWritable(target, function (writable) {
       if (writable) {
@@ -153,7 +153,7 @@ function ncp (source, dest, options, callback) {
     });
   }
 
-  function mkDir(dir, target) {
+  mkDir = (dir, target) => {
     fs.mkdir(target, dir.mode, function (err) {
       if (err) {
         return onError(err);
@@ -162,7 +162,7 @@ function ncp (source, dest, options, callback) {
     });
   }
 
-  function copyDir(dir) {
+  copyDir = (dir) => {
     fs.readdir(dir, function (err, items) {
       if (err) {
         return onError(err);
@@ -174,7 +174,7 @@ function ncp (source, dest, options, callback) {
     });
   }
 
-  function onLink(link) {
+  onLink = (link) => {
     var target = link.replace(currentPath, targetPath);
     fs.readlink(link, function (err, resolvedPath) {
       if (err) {
@@ -184,7 +184,7 @@ function ncp (source, dest, options, callback) {
     });
   }
 
-  function checkLink(resolvedPath, target) {
+  checkLink = (resolvedPath, target) => {
     if (dereference) {
       resolvedPath = path.resolve(basePath, resolvedPath);
     }
@@ -209,7 +209,7 @@ function ncp (source, dest, options, callback) {
     });
   }
 
-  function makeLink(linkPath, target) {
+  makeLink = (linkPath, target) => {
     fs.symlink(linkPath, target, function (err) {
       if (err) {
         return onError(err);
@@ -218,7 +218,7 @@ function ncp (source, dest, options, callback) {
     });
   }
 
-  function isWritable(path, done) {
+  isWritable = (path, done) => {
     fs.lstat(path, function (err) {
       if (err) {
         if (err.code === 'ENOENT') return done(true);
@@ -228,7 +228,7 @@ function ncp (source, dest, options, callback) {
     });
   }
 
-  function onError(err) {
+  onError = (err) => {
     if (options.stopOnError) {
       return cback(err);
     }
@@ -247,7 +247,7 @@ function ncp (source, dest, options, callback) {
     return cb();
   }
 
-  function cb(skipped) {
+  cb = (skipped) => {
     if (!skipped) running--;
     finished++;
     if ((started === finished) && (running === 0)) {