                        課程
                    
                        /前端開發(fā)
                        
                            /HTML/CSS
                        
                        /導(dǎo)航條菜單的制作

為什么我的代碼死活運行不出來效果。。。。幾乎完全copy的

<!DOCTYPE?html>
<html>
??<head>
????<meta?charset="utf-8">
????<title>導(dǎo)航欄</title>

????<style?media="screen">
??????ul{
????????list-style:?none;
????????width:?800px;
????????height:50px;
????????border-bottom:?5px?solid?rgb(14,?79,?126);
??????}
??????a{
????????text-align:?center;
????????display:?block;
????????width:?100px;
????????text-decoration:?none;
????????font-family:?黑體;
????????color:?rgb(0,0,0);
????????line-height:?30px;
????????font-size:?20px;
????????background:?rgb(189,?108,?108);
????????padding:?5px;
????????border-top-right-radius:?8px;
????????border-top-left-radius:?8px;
??????}
??????/*a:hover,a.on{
????????background:?rgb(29,?62,?122);
????????color:white;
????????width:?150px;
??????}*/
??????li{
????????float:?left;
????????margin-top:10px;

??????}
????</style>
????<script?type="text/javascript">
??????window.onload=function(){
????????var?oNav=document.getElementsByTagName('ul')[0];
??????	var?aA=oNav.getElementsByTagName('a');
????????for(var?i=0;?i<aA.length;?i++){
??????		aA[i].onmouseover=function(){
??????			if(this.className!="on"){
??????				clearInterval(this.timer);
??????				var?This=this;
??????				This.time=setInterval(function(){
??????					This.style.width=This.offsetWidth+8+"px";
??????					if(This.offsetWidth>=120)
??????					clearInterval(This.time);
??????				},30)
??????			}
??????		}
??????		aA[i].onmouseout=function(){
??????			if(this.className!="on"){
??????				clearInterval(this.time);
??????				var?This=this;
??????				this.time=setInterval(function(){
??????					This.style.width=This.offsetWidth-8+"px";
??????					if(This.offsetWidth<=80){
??????						This.style.width='80px';
??????						clearInterval(This.time);
??????					}
??????				},30)
??????			}
??????		}
??????	}
??????}
????</script>
??</head>
??<body>
????<ul>
??????<li><a?class="on"?href="#">首&nbsp&nbsp&nbsp&nbsp頁</a></li>
??????<li><a?href="#">新聞快訊</a></li>
??????<li><a?href="#">產(chǎn)品展示</a></li>
??????<li><a?href="#">售后服務(wù)</a></li>
??????<li><a?href="#">聯(lián)系我們</a></li>
????</ul>
??</body>
</html>