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

老師你好，我的代碼執行不出來怎么就運行不出來看看就是

<!doctype html>
<html>
<head>
??? <meta charset="UTF-8">
?<title>Document</title>
?<style>
? *{margin:0;padding:0;}
???? .head{font-size:12px;padding:6px 0 0 10px;}
???? #login_box{width:300px;height:150px;background:#eee;
???? border:1px solid #ccc;position:absolute;left:50%;top:50%;margin-left:-150px;margin-top:-75px;display:none;}
???? #login_box p{height:20px;border-bottom:1px solid #ccc;font-size:12px;padding:6px 0 0 5px;font-weight:bold;}
???? #close{width:14px;height:14px;background:url(close.png) no-repeat;position:absolute;right:4px;top:6px;}
?</style>
?<script>
????? window.onload=function(){
????? ?var login_btn=document.getElementById('login'),
????? ???? login_box=document.getElementById('login_box'),
????? ???? close=document.getElementById('close');
????? ?// 封裝添加事件監聽程序
??????? function addEvent(ele,type,hander){
?????????? // 執行代碼
?????????? if(ele.addEventListener){
????????????? ele.addEventListener(type,hander,false);
?????????? }else if(ele.attachEvent){
?????????????? ele.attachEvent('on'+type,hander);
?????????? }else{
?????????????? ele['on'+type]=hander;
??????????????
?????????? }??
??????????
????? ?}
??????? // 顯示登錄層函數
????? ?function showLogin(){
????? ??// 執行代碼
??????????? login_box.style.display='block';
??????? }
??????? // 隱藏登錄層函數
??????? function hideLogin(){
????????? // 執行代碼
????????? login_box.style.display='none';
??????? }
??????? //點擊登錄按鈕顯示登錄層
??????? addEvent(login_btn,'click',showLogin);
???????
??????? // 執行代碼
??????? //點擊關閉按鈕隱藏登錄層
??????? // 執行代碼
????? addEvent(login_box,'click',hideLogin);
?</script>
</head>
<body>
?<div>親，您好！<input type="button" value="登錄" id="login"></div>
?<div id="login_box">
??<p>用戶登錄</p><span id="close"></span>
?</div>
</body>
</html>