<script type="text/javascript"> function OnbtnClick() { var txtCount=document.getElementById("div_tab").getElementsByTagName("li").length; alert(txtCount); } </script> <input type="button" onclick="OnbtnClick()" value="获取当前打开的菜单数量" style="border-bottom-style:inset;"/> <div id="style_one"> <ul class="clearfix" id="div_tab"></ul> <!--菜单列表 --> <div id="div_pannel" style="height:610px;"> </div> </div>