code: function (elem, event, listener) {
  		if (elem.detachEvent) {	// IE only.  The "on" is mandatory.
  			elem.detachEvent("on" + event, listener);
  		} else { // Other browsers.
  			elem.removeEventListener(event, listener, false);
  		}
  	}
docs: Removes a listener callback from a DOM element which is fired on a specified event.