/// <summary>

        /// 返回类别列表

        /// </summary>

        /// <param name="parent_id">父类别ID</param>
　　　　 /// <param name="channel_id">频道ID</param>

        /// <returns>DataTable</returns>

        protected DataTable get_category_list(int parent_id, string channel_id)

        {

            return new BLL.article_category().GetList(parent_id, int.Parse(channel_id));

        }

  <ul id="navigation">

    <li><a href="<%linkurl("index")%>">网站首页</a></li>

   <%set DataTable categorylist=get_category()%>

      <%loop category categorylist%>

         <li onmouseover="displaySubMenu(this)" onmouseout="hideSubMenu(this)">

         <a href="/{category[name]}_index.html">{category[title]}</a>

         <ul>

      <%set DataTable arc_categorylist=get_category_list(0,{category[id]})%>

         <%loop arc_category arc_categorylist%>

        <li> <a href="/{category[name]}/list-{arc_category[id]}.html">{arc_category[title]}</a></li>

         <%/loop%>

         </ul>

         </li>

      <%/loop%>

      </ul>

 <script type="text/javascript">

     function displaySubMenu(li) {

         var subMenu = li.getElementsByTagName("ul")[0];

         subMenu.style.display = "block";

     }

     function hideSubMenu(li) {

         var subMenu = li.getElementsByTagName("ul")[0];

         subMenu.style.display = "none";

     }

</script>