源代码是这样的：
我改变的代码不能正常的远行了，我想改变他在两个地方显出的。
这个是源代码，下面的是我改的（有错的代码）
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" " http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns=" http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>仿网易的滑动门技术，用DIV+CSS技术实现</title>
<style type="text/css">
<!--
#header {
background-color: #F8F4EF;
height: 200px;
width: 400px;
margin: 0px;
padding: 0px;
border: 1px solid #ECE1D5;
font-family: "宋体";
font-size: 12px;
}
#menu {
margin: 0px;
padding: 0px;
list-style-type: none;
}
#menu li {
display: block;
width: 100px;
text-align: center;
float: left;
margin: 0px;
padding-top: 0.2em;
padding-right: 0px;
padding-bottom: 0.2em;
padding-left: 0px;
cursor: hand;
}
.sec1 { background-color: #FFFFCC;}
.sec2 { background-color: #00CCFF;}
.block { display: block;}
.unblock { display: none;}
-->
</style>
</head>
<body>
<script language=javascript>
function secBoard(n)
{
for(i=0;i<menu.childNodes.length;i++)
menu.childNodes[i].className="sec1";
menu.childNodes[n].className="sec2";
for(i=0;i<main.childNodes.length;i++)
main.childNodes[i].style.display="none";
main.childNodes[n].style.display="block";
}
</script>
<div id="header">
<ul id="menu">
<li onMouseOver="secBoard(0)" class="sec2">最新新闻</li>
<li onMouseOver="secBoard(1)" class="sec1">最新文章</li>
<li onMouseOver="secBoard(2)" class="sec1">最新日志</li>
<li onMouseOver="secBoard(3)" class="sec1">论坛新帖</li>
</ul>
<!--内容显示区域-->
<ul id="main">
<li class="block">第一个内容</li>
<li class="unblock">第二个内容</li>
<li class="unblock">第三个内容</li>
<li class="unblock">第四个内容</li>
</ul>
<!--内容显示区域-->
</div>
</body>
</html>
------------------------------------------
--------------------------------------
我改变了这样：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" " http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns=" http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>仿网易的滑动门技术，用DIV+CSS技术实现</title>
<style type="text/css">
<!--
#header {
background-color: #F8F4EF;
height: 200px;
width: 400px;
margin: 0px;
padding: 0px;
border: 1px solid #ECE1D5;
font-family: "宋体";
font-size: 12px;
}
#menu {
margin: 0px;
padding: 0px;
list-style-type: none;
}
#menu li {
display: block;
width: 100px;
text-align: center;
float: left;
margin: 0px;
padding-top: 0.2em;
padding-right: 0px;
padding-bottom: 0.2em;
padding-left: 0px;
cursor: hand;
}
.sec1 { background-color: #FFFFCC;}
.sec2 { background-color: #00CCFF;}
.block { display: block;}
.unblock { display: none;}
-->
</style>
</head>
<body>
<div align="center">
<table border="1" cellpadding="0" cellspacing="0" width="985" id="table1" height="335">
<tr>
<td width="491"> <script language=javascript>
function secBoard(n)
{
for(i=0;i<menu.childNodes.length;i++)
menu.childNodes[i].className="sec1";
menu.childNodes[n].className="sec2";
for(i=0;i<main.childNodes.length;i++)
main.childNodes[i].style.display="none";
main.childNodes[n].style.display="block";
}
</script>
<div id="header">
<ul id="menu">
<li onMouseOver="secBoard(0)" class="sec2">Soso1</li>
<li onMouseOver="secBoard(1)" class="sec1">soso2</li>
<li onMouseOver="secBoard(2)" class="sec1">soso3</li>
<li onMouseOver="secBoard(3)" class="sec1">soso4</li>
</ul>
<!--内容显示区域-->
<ul id="main">
<li class="block">第一个内容</li>
<li class="unblock">第二个内容</li>
<li class="unblock">第三个内容</li>
<li class="unblock">第四个内容</li>
</ul>
<!--内容显示区域-->
</div></td>
<td width="492">
<script language=javascript>
function secBoardjan(n)
{
for(i=0;i<menu.childNodes.length;i++)
menu.childNodes[i].className="sec1";
menu.childNodes[n].className="sec2";
for(i=0;i<main.childNodes.length;i++)
main.childNodes[i].style.display="none";
main.childNodes[n].style.display="block";
}
</script>
<div id="header">
<ul id="menu">
<li onMouseOver="secBoardjan(4)" class="sec2">QQ1</li>
<li onMouseOver="secBoardjan(5)" class="sec1">QQ2</li>
<li onMouseOver="secBoardjan(6)" class="sec1">QQ3</li>
<li onMouseOver="secBoardjan(7)" class="sec1">QQ4</li>
</ul>
<!--内容显示区域-->
<ul id="main">
<li class="block">QQ111111111111111111</li>
<li class="unblock">QQ222222222222222222</li>
<li class="unblock">QQ3333333333333333333</li>
<li class="unblock">QQ444444444444444444444444</li>
</ul>
<!--内容显示区域-->
</div></td>
</tr>
</table>
</div>
</body>
</html>
-----------------------------
-------------------------
但是代码不能正常的远行了，我想改变他在两个地方显出的