<body>
<input type="button" value="按钮" id="btn" />
<script>
function showMessage(){
alert("hello world!");
}
var eventUtil = {
//添加句柄
addHandler:function(element,type,handler){
if(element.addEventListener){//DOM2级事件处理程序判断
element.addEventListener(type,handler,false);
}else if(element.attachEvent){//IE级事件处理程序判断
element.attachEvent('on'+type,handler);
}else{//DOM0级事件处理程序判断
element['on'+type]=handler;
}
}
//删除句柄
removeHandler:function(element,type,handler){
if(element.removeEventListener){//DOM2级事件处理程序判断
element.removeEventListener(type,handler,false);
}else if(element.detachEvent){//IE级事件处理程序判断
element.detachEvent('on'+type,handler);
}else{//DOM0级事件处理程序判断
element['on'+type]=null;
}
}
}
eventUtil.addHandler(btn,'click',showMessage);
</script>
</body>