<a onclick="changeclo(this)">添加项目</a>
<a onclick="changeclo(this)">修改项目</a>
<a onclick="changeclo(this)">查看项目</a> 
<Style type="text/css"> 
.a1
{text-decoration: none; color:#ff0000}
</Style> 
<SCRIPT> 
function changeclo(obj)
{
var lab = document.getElementsByTagName("a");
for (var i = 0; i < lab.length; i++) 

{
lab[i].className="";
}
obj.className="a1";
}
</SCRIPT> 
点击测试: