var eventUtil = {
			// 添加句柄
			addHandler:function(element,type,handler){
				if(element.addEventListener){
					element.addEventListener(type,handler,false);
				}else if(element.attachEvent){
					element.attachEvent('on'+type,handler);
				}else{
					element['on'+type]=handler;
				}
			},
			// 删除句柄
			removeHandler:function(element,type,handler){
				if(element.removeEventListener){
					element.removeEventListener(type,handler,false);
				}else if(element.detachEvent){
					element.detachEvent('on'+type,handler);
				}else{
					element['on'+type]=null;
				}
			}
		}
		showMes4(){
			alert("跨浏览器的click事件");
		}
		
		eventUtil.addHandler(btn5,'click',showMes4);

body部分

<input type="button" id="btn5" value="按钮5"><br/>