If you ever need to whip up a quick event emitter, and you already have jQuery, you can piggyback off jQuery's events:

eventEmitterJquery.js

// event emitter factory built off jQuery events
eventEmitter = function eventEmitter () {
  var pipe = $({}),
    api = {
      trigger: function trigger (event, data) {
        pipe.trigger({
          type: event, 
          customData: data
        });
      },
      on: function on (event, handler) {
        pipe.on(event, function (e) {
          handler(e.customData);
        });
      },
      off: function off (event) {
        pipe.off(event);
      },
      once: function once (event, handler) {
        pipe.one(event, function (e) {
          handler(e.customData);
        });
      }
    };
  return api;
};