UpdatePanel control -
<asp:ScriptManager runat="server" ID="ScriptManagers"
EnablePartialRendering="True" />
<h1>Gridview data:</h1>
<p>Page rendered at <%= DateTime.Now.ToLongTimeString() %>.</p>
<asp:UpdatePanel runat="server" ID="TheUpdatePanel">
<ContentTemplate>
<asp:GridView id="Grid" runat="server"
AllowPaging="True" PageSize="10"
onpageindexchanging="Grid_PageIndexChanging">
</asp:GridView>
<p>Grid rendered at <%= DateTime.Now.ToLongTimeString() %>
</p>
</ContentTemplate>
</asp:UpdatePanel>
in the above codes The UpdatePanel allows the content
within its <ContentTemplate> tags to be updated using Ajax
without reloading the page.