DataGrid Template question

[Ashish]

i had posted a related question earlier, i think this should be simple,
how can i get hold of a dropdownlist which is emmbedded in a
HeaderTemplate of a DataGrid.
The code is somehat time
<asp:datagrid id="DataGrid1" runat="server">
<Columns><asp:TemplateColumn>
<HeaderTemplate>
<asp:DropDownList id="Dropdownlist1" Runat="server" DataSource='<%#
NextLevel %>' DataValueField="id" DataTextField="Name">
</asp:DropDownList>
</HeaderTemplate>
<ItemTemplate>
</ItemTemplate>
</asp:TemplateColumn>
</Columns>
</asp:datagrid>

how can i access the DropDownList1 from code behind ?

many thanks

-ashish