//这是前台代码

<script language="javascript" type="text/javascript">
        function show(c_Str)
        {
          if(document.all.(c_Str).style.display=='none')
          {document.all.(c_Str).style.display='block';}
          else{document.all(c_Str).style.display='none';}
        }

        function high()
        {
          if (event.srcElement.className=="k")
          {
            event.srcElement.style.background="336699"
            event.srcElement.style.color="white"
          }
        }
        function low()
        {
          if (event.srcElement.className=="k"){
          event.srcElement.style.background="99CCFF"
          event.srcElement.style.color=""
        }

    </script>

<div id="bendi" runat="server">
 </div>

 //这是后台代码

 protected void Page_Load(object sender, EventArgs e)
    {

ben.Append("<div class=\"up\" onclick=\"show('aaa" + j + "')\" >" + channelClass2.Rows[j]["MIDDLECATEGORY_NAME"] + "</div>");

ben.Append("<div id=\"aaa" + j + "\" onmouseover=high() onmouseout=low()  style=\"display:none\">");

ben.Append("</div>");

bendi.InnerHtml = ben.ToString(); 

   }