createGuid.js

function() {
         // http://stackoverflow.com/a/2117523/571637
         return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
            /* jshint bitwise: false */
            var r = Math.random() * 16 | 0;
            var v = c === 'x' ? r : (r & 0x3 | 0x8);
            return v.toString(16);
         });
      }