跨浏览器事件处理函数

addEvent.repeat = function(type,fn){
	for(var i in type){
		if(type[i] == fn){
			return true;
		}
		return false;
	}
};
addEvent.fn = function(){
	var e = addEvent.fixEvent(window.event);
	for(var i in this.events[e.type]){
		this.events[e.type][i].call(this,e);
	}
};
//fixEvent : 处理IE的事件对象
addEvent.fixEvent = function(e){
	e.preventDefault = function(){
		e.returnValue = false;
	};
	e.stopPropagation = function(){
		e.cancelBubble = true;
	};
	e.target = e.srcElement;
	if('mouseover' == e.type){
		e.relatedTarget = e.fromElement;
	}
	if('mouseout' == e.type){
		e.relatedTarget = e.toElement;
	}
	return e;
};
//添加事件
function addEvent(obj,type,fn){
	if(typeof obj.addEventListener != 'undefined'){
		obj.addEventListener(type,fn,false);
	}else{
		if(!obj.events) obj.events = {};
		if(!obj.events[type]){
			obj.events[type] = [];
		}
		if(!addEvent.repeat(obj.events[type],fn)){
			obj.events[type].push(fn);
		}
		obj['on' + type] = addEvent.fn;
	}
}
//移除事件
function removeEvent(obj,type,fn){
	if(typeof obj.removeEventListener != 'undefined'){
		obj.removeEventListener(type,fn,false);
	}else{
		if(obj.events){
			for(var i in obj.events[type]){
				if(obj.events[type][i] == fn){
					delete obj.events[type][i];
				}
			}
		}
	}
}

var test = document.getElementById("test");

//给test元素添加点击事件，执行fn1
addEvent(test,'click',fn1);
//给test元素移除点击事件
removeEvent(test,'click',fn1);

function fn1(){
	alert("fn1");
}