ListBox inside grid view

[SimonZ]

If I have gridView and one of the columns is template cpolumn, where I have
listBox in edit mode:

<asp:TemplateFi eld>
<HeaderTemplate >CategorName: </HeaderTemplate>
<ItemTemplate >
<asp:Label runat="server" text='<%#
Eval("CategoryN ame")%>'></asp:Label>
</ItemTemplate>
<EditItemTempla te>
<asp:ListBox Rows=1 runat="server" ID=lstCat
DataSourceID="S qlDataSource3" DataValueField= "CategoryID "
DataTextField=" CategoryName"></asp:ListBox>
</EditItemTemplat e>
</asp:TemplateFie ld>

In sqlDataSource I have defined update parameter:
<asp:ControlPar ameter ControlID="lstC at" Name="CategoryI D"
PropertyName="S electedValue" Type="Int32" />
When I click Update I can't read the value from my list box:
Could not find control 'lstCat' in ControlParamete r 'CategoryID'.

How can I read the value from control which is inside grid view?

If I move this control outside the gridView it works.

It looks like that you can't read the controls which are inside other
controls.

Any idea?
Regards,Simon