<a href="1.aspx?id=1" id="1" target="_parent">""</a>
<a href="1.aspx?id=2" id="2" target="_parent">""</a>
<a href="1.aspx?id=3" id="3" target="_parent">""</a>

<script>
&(document).ready(function(){
var id = windows.ulr.substring(windows.ulr.IndeOf("?id="),1) //取得id值
var currtA = document.getElementById(id); //取得當前被點擊a標簽
if(currtA != null)
currtA.style.color = "#f00";
});
</script>

<a href="#" onclick="changeCss(this)">""</a>

<script>
function changeCss(obj){
var alist = document.getElementsByTagName("a");
for(var i =0;i < alist.Length;i++){
alist[i].style.color = "#000"; //給所有a標簽賦原色
}
obj.style.color = "#f00"; //令當前標簽高亮
}
//當然也可以用Jquery的$("a").removeCss() 和addCss()來實現
</script>