<div class="aa">

<div class="warp" onclick="select()">     <div class="pic">                                  </div>     <div class="text">                                 </div>     <div class="date"></div> </div>

</div>
<div class="aa">

<div class="warp" onclick="select()">     <div class="pic">                                  </div>     <div class="text">                                 </div>     <div class="date"></div> </div>

</div>

当我点击的时候使被点击的div 的class属性值变成class="warp grey".
不要用this对象。怎么做呀？谢谢