                        課程
                    
                        /前端開發
                        
                            /JavaScript
                        
                        /DOM事件探秘

運行不了，單詞都核對過了

<!DOCTYPE?html>
<html>
<head>
<meta?charset="UTF-8">
<title>Document</title>
</head>
<body>
<div?id="box">
????<input?type="button"?value="按鈕"?id="btn">
</div>
<script>
????var?btn=getElementById("btn");?//獲取id
????function?showMes()?{?//執行的函數
????????alert("hello?world!");
????}
????var?eventUtil={
????????//添加句柄
????????addHandler:function(element,type,handler){
????????????if(element.attachEvent){
????????????????element.attachEvent('on'+type,handler);
????????????}else?if(element.addEventListener){
????????????????element.addEventListener(type,handler,false);
????????????}else{
????????????????element['on'+type]=handler;
????????????}
????????},
????????//刪除句柄
????????removeHandler:function(element,type,handler){
????????????if(element.detachEvent){
????????????????element.detachEvent('on'+type,handler);
????????????}else?if(element.removeEventListener){
????????????????element.removeEventListener(type,handler,false);
????????????}else{
????????????????element['on'+type]=null;
????????????}
????????}
????}
????eventUtil.addHandler(btn,'click',showMes);?//執行添加句柄函數
????//eventUtil.removeHandler(btn,'click',showMes);?//執行刪除句柄函數
</script>
</body>
</html>