diff --git a/climbgrades/climbgrades.js b/climbgrades/climbgrades.js
index f60b0af..bed2b2c 100644
--- a/climbgrades/climbgrades.js
+++ b/climbgrades/climbgrades.js
@@ -1,4 +1,4 @@
-
+// Copyright 2014, Michael Stanton.
 var ClimbGrades = (function() {
 
   // index UIAA           YDS             French
@@ -148,54 +148,6 @@ var ClimbGrades = (function() {
   return module;
 }());
 
+// Uncomment this if you are embedding in a web page.
 exports = module.exports = ClimbGrades;
 
-/*
-function ParseSportGradeFromUIAA(uiaa) {
-  var trimmed_uiaa = uiaa.trim();
-  var index = ClimbGrades.ToIndex(trimmed_uiaa, ClimbGrades.GRADE.UIAA);
-  return index;
-}
-
-
-function UIAAFromSportGrade(grade) {
-  var uiaa_string = ClimbGrades.FromIndex(grade, ClimbGrades.GRADE.UIAA);
-  return uiaa_string;
-}
-
-function print(str) {
-  console.log(str);
-}
-
-
-function Main() {
-  var arguments = process.argv.slice(2);
-  if (arguments.length == 0) {
-    console.log("Usage: " + process.argv[1] + 
-                " <space separated UIAA graded climbs>");
-    return 1;
-  }
-
-  accum = 0.0;
-  climb_count = 0;
-  for (var i = 0; i < arguments.length; i++) {
-    var arg = arguments[i];
-    sport_grade = ParseSportGradeFromUIAA(arg);
-    if (sport_grade < 0) {
-      print("Expression " + arg + " could not be parsed");
-    } else {
-      print(arg + " -> " + sport_grade);
-      climb_count = climb_count + 1;
-      accum = accum + sport_grade;
-    }
-  }
-
-  average = Math.round(accum / climb_count);
-  str_average_rating = UIAAFromSportGrade(average);
-  print("UIAA average rating -> " + str_average_rating);
-  print("Average sport grade -> " + average);
-  print("Total effort        -> " + accum);
-}
-
-Main();
-*/
diff --git a/climbgrades/grades.js b/climbgrades/grades.js
new file mode 100644
index 0000000..f775f68
--- /dev/null
+++ b/climbgrades/grades.js
@@ -0,0 +1,78 @@
+// Copyright 2014, Michael Stanton.
+var ClimbGrades = require("./climbgrades");
+
+function ParseSportGradeFromUIAA(uiaa) {
+  var trimmed_uiaa = uiaa.trim();
+  var index = ClimbGrades.ToIndex(trimmed_uiaa, ClimbGrades.GRADE.UIAA);
+  return index;
+}
+
+
+function UIAAFromSportGrade(grade) {
+  var uiaa_string = ClimbGrades.FromIndex(grade, ClimbGrades.GRADE.UIAA);
+  return uiaa_string;
+}
+
+function print(str) {
+  console.log(str);
+}
+
+
+function GetGrade(str) {
+  str = str.trim().toLowerCase();
+  if (str === "uiaa") return ClimbGrades.GRADE.UIAA;
+  else if (str === "yds") return ClimbGrades.GRADE.YDS;
+  else if (str === "french") return ClimbGrades.GRADE.FRENCH;
+  throw new TypeError(str + " is not a valid grade.");
+}
+
+
+function Main() {
+  var arguments = process.argv.slice(2);
+  if (arguments.length < 3) {
+    print("Usage: " + process.argv[1] +
+          "<from> <to> <space separated graded climbs>");
+    print("<from> and <to> are UIAA, YDS or French");
+    return 1;
+  }
+
+  accum = 0.0;
+  climb_count = 0;
+  var from = GetGrade(arguments[0]);
+  var to = GetGrade(arguments[1]);
+  var output = [];
+  for (var i = 2; i < arguments.length; i++) {
+    var arg = arguments[i].trim();
+    try {
+      var index = ClimbGrades.ToIndex(arg, from);
+      if (index < 0) {
+        print("skipping " + arg + ". Couldn't be parsed.");
+      } else {
+        var result = ClimbGrades.FromIndex(index, to);
+        output.push(result);
+        climb_count = climb_count + 1;
+        accum = accum + index;
+      }
+    } catch(e) {
+      print("error occurred: " + e.message);
+    }
+  }
+
+  // print the results
+  var outputStr = "";
+  for (var i = 0; i < output.length; i++) {
+    outputStr += output[i].toString();
+    outputStr += " ";
+  }
+  print(outputStr);
+
+  if (output.length > 1) {
+    average = Math.round(accum / climb_count);
+    average_from = ClimbGrades.FromIndex(average, from);
+    average_to = ClimbGrades.FromIndex(average, to);
+    print("average rating: " + average_from + " (" + from.name + ") " +
+          average_to + " (" + to.name + ")");
+  }
+}
+
+Main();
diff --git a/climbgrades/grades.sh b/climbgrades/grades.sh
new file mode 100755
index 0000000..bb1841f
--- /dev/null
+++ b/climbgrades/grades.sh
@@ -0,0 +1,5 @@
+#!/bin/bash
+# A shell script to wrap the climbgrades utility.
+DIRECT=`dirname $0`/climbgrades
+node $DIRECT/grades.js $@
+