请问下怎么判断一个标签是否被点击了
<li tapmode="active" class="active" onclick="randomSwitchBtn(this,'ordering',0)">
<a class="bottom_btn ordering">订餐</a>
</li>
<li tapmode="active" onclick="randomSwitchBtn(this,'menu',1)">
<a class="bottom_btn menu ">菜单</a>
</li>
<li tapmode="active" onclick="randomSwitchBtn(this,'wealfare',2)">
<a class="bottom_btn welfare ">福利</a>
</li>
<li tapmode="active" onclick="randomSwitchBtn(this,'mine',3)">
<a class="bottom_btn mine ">我的</a>
</li>
function randomSwitchBtn(obj, name, index) {}
怎么判断最后一个li被点击了