JavaScript 利用ClassName实现导航栏效果

<ul id="daohang">
<li><a href="" title="" rel="nofollow"></a></li>
</ul>

<script type="text/javascript">
var odaohang =document.getElementById('daohang');
var oli = odaohang.document.getElementsByTagName("li");
for(var i = 0; i < oli.length; i++)
{
oli[i].className='active'
}
</script>