在asp.net中实现Gridview 表头固定

<script language="javascript">
 function init()
          {
           var tbBody = document.getElementById("<%=GridView2.ClientID%>");
            if(tbBody!=null)
           {
           var tbHead = tbBody.cloneNode(true)
           for(i = tbHead.rows.length -1;i > 1;i--)
            tbHead.deleteRow(i);
         
           divContent.appendChild(tbHead);
           }
          }
          window.onload = init
  </script>
  <div id="divContent">
   
          </div>
          <div id ="divG" style="height: 180px;position: relative; overflow:scroll;">
 <asp:GridView ID="GridView1" runat="server" OnRowCreated="GridView1_OnRowCreated" AllowPaging="true" PageSize="15"
      AutoGenerateColumns="false"  Width="800" ShowHeader ="false"  OnRowDataBound="GridView1_RowDataBound"  DataKeyNames="XTBH">
     <AlternatingRowStyle CssClass="Alternatingback"></AlternatingRowStyle>
        <RowStyle CssClass="griditem"></RowStyle>
         <HeaderStyle BackColor="#CEDDF0" ForeColor="#000000"  Height="26px" />
    &nb