//css样式

.tab_math{ position:relative; z-index:999;}

.mainNav_0121 UL LI .mathSelect{ display:none; background-color:#fff; border:2px solid #0081B1; border-top:none; width:108px; position:absolute; z-index:9999; *left:0px;} .mainNav_0121 UL LI .mathSelect p a{ font-weight:normal; font-size:12px; color:#c00; width:auto;background:url(http://img.eduuu.com/jiajiao/images/index59/reddot.gif) no-repeat 10px 13px; text-align:left; padding-left:20px;} .mainNav_0121 UL LI .mathSelect p a:hover{color:#c00; background:#ffe1e1 url(http://img.eduuu.com/jiajiao/images/index59/reddot.gif) no-repeat 10px 13px;}  html页面

<LI xes_id="head_menu_004" class="tab_math"><A onMouseDown="hits('nav05')"

  href="http://sh.jiajiaoban.com/shiti/" target="_blank">杯赛</A>     <div class="mathSelect tab_con">         <div>             <p><a href="http://baidu.com" target="_blank">中</a></p>             <p><a href="http://ok.com" target="_blank">小</a></p>             <p><a href="http://no.com" target="_blank">大</a></p>         </div>     </div>

  </LI>

js页面

<script type="text/javascript">

    $(function(){                 $('.tab_math').hover(function(){                         $(this).find('.mathSelect').show();                  },function(){                         $(this).find('.mathSelect').hide();                  })     });   </script>