JS例子（好友列表选中）

<style type="text/css">
*{ margin:0px auto;
   padding:0px;}

.tian{ width:300px; 
       height:50px; 
	   text-align:center; 
	   line-height:50px; 
	   vertical-align:middle; 
	   border:1px solid #F00; 
	   margin-top:20px;
	   background-color:blue;}
.tian:hover{ cursor:pointer;}
</style>

　　

body>
   <div>
   <div class="tian"  onmouseover="bian(this)" onmouseout="se(this)" onclick="xuan(this)" xz="0">好</div>
   <div class="tian"  onmouseover="bian(this)" onmouseout="se(this)" onclick="xuan(this)" xz="0">友</div>
   <div class="tian"  onmouseover="bian(this)" onmouseout="se(this)" onclick="xuan(this)" xz="0">列</div>
   <div class="tian"  onmouseover="bian(this)" onmouseout="se(this)" onclick="xuan(this)" xz="0">表</div>
   <div class="tian"  onmouseover="bian(this)" onmouseout="se(this)" onclick="xuan(this)" xz="0">选</div>
   <div class="tian"  onmouseover="bian(this)" onmouseout="se(this)" onclick="xuan(this)" xz="0">中</div>
   </div>
</body>

　　

<script type="text/javascript">

 function bian(a){
	 var sy = document.getElementsByClassName("tian");
       for (var i=0;i<sy.length;i++){
		   if(sy[i].getAttribute("xz")=="0"){
	          sy[i].style.backgroundColor = "blue";}
       }
	    a.style.backgroundColor = "red";
	  }  
	
 function se(b){
	 var sy = document.getElementsByClassName("tian");
       for (var i=0;i<sy.length;i++){
		   if(sy[i].getAttribute("xz")=="0"){
	          sy[i].style.backgroundColor = "blue";}
       }
	 b.style.backgroundColor = "red";
	 }

 function xuan(c){
	 

	var d = document.getElementsByClassName("tian");
	for(var i=0;i<d.length;i++){
		d[i].style.backgroundColor = "blue";
		d[i].setAttribute("xz","0");
	}
	
	c.style.backgroundColor = "red";
	c.setAttribute("xz","1");
    }
</script>