title: Freezing Gridview header not working
body: <p>I need to freeze the grid view header on scrolling grid view. Assigned data's to data table and binding it to gridview called 'report'. I tried a lot, but it is not working.. Can any one help me?</p>
  
  <pre><code>&lt;asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Always" ChildrenAsTriggers="true"&gt;
      &lt;ContentTemplate&gt;
          &lt;center&gt;
             &lt;asp:Label ID="mess" runat="server" Font-Bold="true" ForeColor="Red"&gt;&lt;/asp:Label&gt;
          &lt;/center&gt;                        
          &lt;div class="table_outer_n"&gt;
             &lt;asp:GridView ID="report" runat="server"  Width="100%" HeaderStyle-CssClass="Freezing"&gt;&lt;/asp:GridView&gt;
             &lt;asp:GridView ID="gvDetails" runat="server" Visible="true"&gt;&lt;/asp:GridView&gt; 
          &lt;/div&gt;
       &lt;/ContentTemplate&gt;
       &lt;Triggers&gt;
          &lt;asp:AsyncPostBackTrigger ControlID="DropDownList1" EventName="SelectedIndexChanged" /&gt;
          &lt;asp:PostBackTrigger ControlID="report" /&gt;
          &lt;asp:PostBackTrigger ControlID="gvDetails" /&gt;
          &lt;asp:PostBackTrigger ControlID="btndwn" /&gt;
        &lt;/Triggers&gt;
  &lt;/asp:UpdatePanel&gt; 
  
  //Code behind
  DataTable claims = new DataTable();   
  //.....datatable codes goes here
  dr["REMARKS"] = remarks;
  dr["VALIDATION"] = validation;
  DataRow dr = claims.NewRow();
  claims.Rows.Add(dr);
  
  report.DataSource = claims;
  report.DataBind();
  
  //css
  .Freezing {
     position:relative ;
     top:expression(this.offsetParent.scrollTop);
     z-index: 10;
  }
  </code></pre>