gridview laoding gif while gridview populating data

<asp:updateprogress id="UProgressButton" dynamiclayout="true" runat="server" xmlns:asp="#unknown">
      <progresstemplate>
           <div id="imgdivLoading1" runat="server" class="loader">
                 <img alt="Progress" border="0" src="Images/loading_new.gif" />
           </div>
     </progresstemplate>
</asp:updateprogress>

<asp:updatepanel id="updDataList" runat="server" xmlns:asp="#unknown">
   <contenttemplate>
     <!-- Your Grid View -->
    </contenttemplate>
</asp:updatepanel>