求老师帮忙看一下啊
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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Document</title>
<style type="text/css">
.top-nav
{
font-size: 14px;
font-weight: bold;
list-style: none;
}
.top-nav li
{
float: left;
margin-right: 1px;
}
.top-nav li a
{
line-height: 34px;
text-decoration: none;
background: #3f240e;
color: #fff;
display: block;
width: 80px;
text-align: center;
}
.top-nav ul
{
list-style: none;
display: none;
padding: 0;
position: absolute;
height: 0;
overflow: hidden;
}
.top-nav li a:hover
{
background: url(pic/slide-bg0.png) 0 0 repeat-x;
}
.note
{
color: #3f240e;
display: block;
background: url(pic/slide-bg0.png) 0 0 repeat-x;
}
.corner
{
display: block;
height: 20px;
background: url(pic/corner.png) 31px 0 no-repeat;
}
</style>
<script>
window.onload = function () {
var Lis = document.getElementsByTagName("li");
for (var i = 0; i < Lis.length ; i++) {
Lis[i].onmouseover = function () {
var uL = this.getElementsByTagName("ul")[0];
u.style.display = "block";
if (uL != undefined) {
u.style.display = "block";
AddH(uL.id);
}
}
Lis[i].onmouseleave = function () {
var uL = this.getElementsByTagName("ul")[0];
SubH(uL.id);
}
}
}
function AddH (id) {
var ulList = document.getElementById(id);
var h = ulList.offSetHeight;
h += 1;
if (h<=42)
{
ulList.style.height = h + "px";
setTimeout("AddH('"+id+"')", 10);
}
else {
return;
}
}
function SubH (id) {
var ulList = document.getElementById(id);
var h = ulList.offSetHeight;
h -= 1;
if (h > 0) {
ulList.style.height = h + "px";
setTimeout("SubH('"+id+"')", 10);
}
else
{
ulList.style.display = "none";
return;
}
}
</script>
</head>
<body>
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<li><a href="#"><span>慕课网</span></a></li>
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</html>....
豆芽_0007