I have a series of GridViews in a Tab Panel - databound to a generic List of Business Objects.

The columns in the Gridview are all similar to the following:

<asp:TemplateField HeaderText="Company" SortExpression="Company.ShortName">
    <ItemTemplate>
        <asp:Label ID="lblCompany" runat="server" Text='<%# Bind("Company.ShortName") %>'></asp:Label>
    </ItemTemplate>
    <EditItemTemplate>
        <asp:DropDownList ID="ddlCompany" runat="server"></asp:DropDownList>
    </EditItemTemplate>
</asp:TemplateField>

The GridView generates the "Edit" link at the beginning of the row, all the events fire ok. The problem is that the data is getting long. When in 'display mode', it's fine because the GridView control is smart enough to break some text into multiple lines (in particular Project, Title and Worker names can get pretty long).

The problem come in editing mode. Drop-down lists DON'T break entries into multiple lines (for obvious reasons). Going into Edit ode on a row in the Gridview can make the Griview expand horizontally to twice the screen size (blowing through the width limits in the Master page and CSS but that's only a related problem).

What I need is something like the ModalPopup - but trying to tie it to an ID in an EditItemTemplate gives me errors when the page renders (because the 'ddlXXXX' doesn't exist at the time). In addition I don't know how to dynamically populate the panel so that I can get a response from it (like the ID of the Company they selected).

I'm also trying to avoid javascript and would like this to be a 'pure' aspx/code-behind solution (for simplicity's sake among others).

All the examples I find are of Modal Popups with the panels pre-defined. Even if it (the popup panel) were something like a list of checkboxes, it could be databound to the SortedList I have ready to go and an OK/Cancel button combination to accept or ignore things. I'm just not sure of what goes where.

I'm open to suggestions. Thanks in advance.

EDIT: Final solution looks as follows:

<asp:TemplateField HeaderText="Company" SortExpression="Company.ShortName">
    <ItemTemplate>
        <asp:Label ID="lblCompany" runat="server" Text='<%# Bind("Company.ShortName") %>'></asp:Label>
    </ItemTemplate>
    <EditItemTemplate>
        <asp:LinkButton ID="lnkCompany" runat="server" Text='<%# Bind("Company.ShortName") %>'></asp:LinkButton>
        <asp:Panel ID="pnlCompany" runat="server" style="display:none">
            <div> 
                <asp:DropDownList ID="ddlCompany" runat="server" ></asp:DropDownList>
                <br/> 
                <asp:ImageButton ID="btnOKCo" runat="server" ImageUrl="~/Images/greencheck.gif" OnCommand="PopupButton_Command" CommandName="SelectCO" /> 
                <asp:ImageButton ID="btnCxlCo" runat="server" ImageUrl="~/Images/RedX.gif" /> 
            </div> 
        </asp:Panel>
        <cc1:ModalPopupExtender ID="mpeCompany" runat="server" 
                TargetControlID="lnkCompany" PopupControlID="pnlCompany" 
                BackgroundCssClass="modalBackground" CancelControlID="btnCxlCo" 
                DropShadow="true" PopupDragHandleControlID="pnlCompany" />
    </EditItemTemplate>
</asp:TemplateField>

And in the code-behind, lstIDLabor is the generic List of data lines (of which Company is one of the properties that is also a business object) that is bound to the GridView:

Sub PopupButton_Command(ByVal sender As Object, ByVal e As CommandEventArgs)
    Dim intRow As Integer
    Dim intVal As Integer
    RestoreFromSessionVariables()
    Select Case e.CommandName
        Case "SelectCO"
            intRow = grdIDCostLabor.EditIndex
            Dim ddlCo As DropDownList = CType(grdIDCost.Rows(intRow).FindControl("ddlCompany"), DropDownList)
            intVal = ddlCo.SelectedValue
            lstIDLabor(intRow).CompanyID = intVal
            lstIDLabor(intRow).Company = Company.Read(intVal)
        Case Else
            '
    End Select
    MakeSessionVariables()
    BindGrids()
End Sub