The ContentTemplate

Listing 1. Content that needs to be updated using asynchronous postback operations can be wrapped in an UpdatePanel control's ContentTemplate.

<asp:UpdatePanel id="upCustomers" runat="server">
    <ContentTemplate>
        <asp:GridView id="gvCustomers" runat="Server" AllowSorting="True"
           AllowPaging="True" DataSourceID="sdsCustomers">
            <Columns>
                ...Column definitions omitted for brevity
            </Columns>
        </asp:GridView>
    </ContentTemplate>
</aspUpdatePanel>