function qiehuan(num){
  for(var id = 0;id<=8;id++)
  {
   if(id==num)
   {
    document.getElementById("qh_con"+id).style.display="block";
    document.getElementById("mynav"+id).className="nav_on";
   }
   else
   {
    document.getElementById("qh_con"+id).style.display="none";
    document.getElementById("mynav"+id).className="";
   }
  }
 }
/*以下是折叠式导航菜单的js*/
function switchMenu(curr_id, total_num)
{
    for(var i=0; i<=total_num; i++)
    {
        //二级菜单
        var el = document.getElementById('menu_sub_'+i);

        if(!el) return;

        //一级菜单前面的图片
        var img = document.getElementById('menu_master_'+i);

        if(i == curr_id)
        {
            el.style.display = "block";
            img.src = "open.gif";
        }
        else
        {
            el.style.display = "none";
            img.src = "close.gif";
        }
    }
}