addEventListener for IE8

addEventListener.js

!window.addEventListener && Element.prototype && (function (polyfill) {
	// window.addEventListener, document.addEventListener, <>.addEventListener
	// window.removeEventListener, document.removeEventListener, <>.removeEventListener

	function Event() { [polyfill] }

	Event.prototype.preventDefault = function () {
		this.nativeEvent.returnValue = false;
	};

	Event.prototype.stopPropagation = function () {
		this.nativeEvent.cancelBubble = true;
	};

	function addEventListener(type, listener, useCapture) {
		useCapture = !!useCapture;

		var cite = this;

		cite.__eventListener = cite.__eventListener || {};
		cite.__eventListener[type] = cite.__eventListener[type] || [[],[]];

		if (!cite.__eventListener[type][0].length && !cite.__eventListener[type][1].length) {
			cite.__eventListener['on' + type] = function (nativeEvent) {
				var newEvent = new Event, newNodeList = [], node = nativeEvent.srcElement || cite, property;

				for (property in nativeEvent) {
					newEvent[property] = nativeEvent[property];
				}

				newEvent.currentTarget =  cite;
				newEvent.pageX = nativeEvent.clientX + document.documentElement.scrollLeft;
				newEvent.pageY = nativeEvent.clientY + document.documentElement.scrollTop;
				newEvent.target = node;
				newEvent.timeStamp = +new Date;

				newEvent.nativeEvent = nativeEvent;

				while (node) {
					newNodeList.unshift(node);

					node = node.parentNode;
				}

				for (var a, i = 0; (a = newNodeList[i]); ++i) {
					if (a.__eventListener && a.__eventListener[type]) {
						for (var aa, ii = 0; (aa = a.__eventListener[type][0][ii]); ++ii) {
							aa.call(cite, newEvent);
						}
					}
				}

				newNodeList.reverse();

				for (var a, i = 0; (a = newNodeList[i]) && !nativeEvent.cancelBubble; ++i) {
					if (a.__eventListener && a.__eventListener[type]) {
						for (var aa, ii = 0; (aa = a.__eventListener[type][1][ii]) && !nativeEvent.cancelBubble; ++ii) {
							aa.call(cite, newEvent);
						}
					}
				}

				nativeEvent.cancelBubble = true;
			};

			cite.attachEvent('on' + type, cite.__eventListener['on' + type]);
		}

		cite.__eventListener[type][useCapture ? 0 : 1].push(listener);
	}

	function removeEventListener(type, listener, useCapture) {
		useCapture = !!useCapture;

		var cite = this, a;

		cite.__eventListener = cite.__eventListener || {};
		cite.__eventListener[type] = cite.__eventListener[type] || [[],[]];

		a = cite.__eventListener[type][useCapture ? 0 : 1];

		for (eventIndex = a.length - 1, eventLength = -1; eventIndex > eventLength; --eventIndex) {
			if (a[eventIndex] == listener) {
				a.splice(eventIndex, 1)[0][1];
			}
		}

		if (!cite.__eventListener[type][0].length && !cite.__eventListener[type][1].length) {
			cite.detachEvent('on' + type, cite.__eventListener['on' + type]);
		}
	}

	window.constructor.prototype.addEventListener = document.constructor.prototype.addEventListener = Element.prototype.addEventListener = addEventListener;
	window.constructor.prototype.removeEventListener = document.constructor.prototype.removeEventListener = Element.prototype.removeEventListener = removeEventListener;
})();

Demo

http://jsfiddle.net/GuQaV/show/

how do？