function (elem, eventName, callback) {
		var listener = function (event) {
			event = event || window.event;
			var target = event.target || event.srcElement;
			var block = callback.apply(elem, [event, target]);
			if (block === false) {
				if (!!event.preventDefault) event.preventDefault();
				else {
					event.returnValue = false;
					event.cancelBubble = true;
				}
			}
			return block;
		};
		if (elem.attachEvent) { // IE only.  The "on" is mandatory.
			elem.attachEvent("on" + eventName, listener);
		} else { // Other browsers.
			elem.addEventListener(eventName, listener, false);
		}
		return listener;
	}
function (elem, eventName, callback) {
		var listener = function (event) {
			event = event || window.event;
			var target = event.target || event.srcElement;
			var block = callback.apply(elem, [event, target]);
			if (block === false) {
				if (!!event.preventDefault) event.preventDefault();
				else {
					event.returnValue = false;
					event.cancelBubble = true;
				}
			}
			return block;
		};
		if (elem.attachEvent) { 
			elem.attachEvent("on" + eventName, listener);
		} else { 
			elem.addEventListener(eventName, listener, false);
		}
		return listener;
	}
function ( elem , eventName , callback ) { var listener = function ( event ) { event = event || window . event ; var target = event . target || event . srcElement ; var block = callback . apply ( elem , [ event , target ] ) ; if ( block === false ) { if ( ! ! event . preventDefault ) event . preventDefault ( ) ; else { event . returnValue = false ; event . cancelBubble = true ; } } return block ; } ; if ( elem . attachEvent ) { // IE only.  The "on" is mandatory. elem . attachEvent ( "on" + eventName , listener ) ; } else { // Other browsers. elem . addEventListener ( eventName , listener , false ) ; } return listener ; }
Adds a listener callback to a DOM element which is fired on a specified event.  Callback is sent the event object and the element that triggered the event
Adds a listener callback to a DOM element which is fired on a specified event . Callback is sent the event object and the element that triggered the event