var xmlHttpHead;
        function createXMLHttpHeadRequest()
        {
            if(window.ActiveXObject)
            {
                xmlHttpHead = new ActiveXObject("Microsoft.XMLHTTP");
            }
            else if(window.XMLHttpRequest)
            {
                xmlHttpHead = new XMLHttpRequest();
            }
        }

    var url= "../services/school/GetHead.ashx?rnd="+parseInt(Math.random()*10000)+1;
    createXMLHttpHeadRequest();
    xmlHttpHead.open("GET",url,true);
    xmlHttpHead.onreadystatechange=showHeadResult;
    xmlHttpHead.send(null);

   function showHeadResult()
        {
           if(xmlHttpHead.readyState==1)
            { 
            }
            if(xmlHttpHead.readyState==4)
            {
          //  alert(xmlHttpHead.status);
                if(xmlHttpHead.status==200)
                {
                var rs=xmlHttpHead.responseText;
             //   alert(rs);
                document.getElementById("div_HeadhInfo").innerHTML=rs;
                }
                else
                {
                  document.getElementById("div_HeadhInfo").innerHTML="加载失败";
                }
            }
        }