引用detailview内部控件？

[dedezhao]

如何在代码页引用PopupControlExtender1 和Calendar1 控件？
<asp:DetailsView ID="DetailsView2" runat="server" AutoGenerateRows="False" BackColor="LightGoldenrodYellow"
BorderColor="Tan" BorderWidth="1px" CellPadding="2" DataKeyNames="username" DataSourceID="SqlDataSource1"
ForeColor="Black" GridLines="None" Height="50px" Width="621px">

<Fields>
<asp:TemplateField>

<EditItemTemplate>
<asp:TextBox ID="birthdayTextBox" runat="server" Text='<%# Bind("birthday") %>'></asp:TextBox>
<ajax:PopupControlExtender ID="PopupControlExtender1" runat="server"
TargetControlID="birthdayTextBox" PopupControlID="Panel1">
</ajax:PopupControlExtender>
<asp:Panel ID="Panel1" runat="server" Height="50px" Width="125px">
<asp:UpdatePanel id="UpdatePanel1" runat="server">
<contenttemplate>
<asp:Calendar id="Calendar1" runat="server" OnSelectionChanged="Calendar1_SelectionChanged"></asp:Calendar>
</contenttemplate>
</asp:UpdatePanel>
</asp:Panel>

</EditItemTemplate>
</asp:TemplateField>
</Fields>

</asp:DetailsView>

[bradring]

(PopupControlExtender)DetailsView2.TemplateControl.FindControl("PopupControlExtender1")