(function () {
  if (window.CustomEvent) return false;
  function CustomEvent(event, params) {
    params = params || {
      bubbles: false, cancelable: false, detail: undefined
    };
    var evt = document.createEvent( 'CustomEvent' );
    evt.initCustomEvent(
      event, params.bubbles, params.cancelable, params.detail
    );
    return evt;
  }
  CustomEvent.prototype = window.Event.prototype;
  window.CustomEvent = CustomEvent;
})();