Javascript的Tab标签页变换

<script>
function changeJobTab(tabIndex)
{
tabJobCount = 4;
for (i = 1; i <= tabJobCount; i++)
{
tab = document.getElementById("JobTab" + i);
content = document.getElementById("JobDescription" + i);

if (i == tabIndex)
{
tab.className = "ActiveJobTab";
content.className = "ActiveJobDescription";
}
else
{
tab.className = "";
content.className = "HiddenJobDescription";
}
}
}
</script>
<div id="zhaopin">
<div id="zptitle"><a href="http://job.csdn.net" target="_blank" >人才招聘榜</a></div>
<div id="zpnav">
<ul id="JobTab">
<li>
<a id="JobTab1" onclick="changeJobTab(1); return false;" class="ActiveJobTab" href="#">企业榜</a>
</li>
<li>
<a id="JobTab2" onclick="changeJobTab(2); return false;" href="#">职位榜</a>
</li>
<li>
<a id="JobTab3" onclick="changeJobTab(3); return false;" href="#">新闻榜</a>
</li>
<li>
<a id="JobTab4" onclick="changeJobTab(4); return false;" href="#">简历榜</a>
</li>
</ul>
</div>
</div>
<dl class="RightContentBlock" id="SpecRecomm">
<dd id="JobInfomation_Description">
<ul>
<div id="JobDescription1" class="ActiveJobDescription" >
<li></li>
</div>
<div id="JobDescription2" class="HiddenJobDescription" >
<li></li>
</div>
<div id="JobDescription3" class="HiddenJobDescription" >
<li></li>
</div>
<div id="JobDescription4" class="HiddenJobDescription" >
<li></li>
</div>
</ul>
</dd>
</dl>