Validaion Controls

[Strider]

I generate a table on the fly in my page. For each row i have a radiobutton so the user can select an item on the table to view.

How can i add a validation control to check whether the user has selected a row in my table.

Currently i validate the control when the user hits the view button but when the button is click the tables data is not reloaded cos of the postback, maybe i should cache that?

While (l_e.MoveNext = True)
                    l_order = CType(l_e.Current, Order)
                    Dim detailsRow As TableRow = New TableRow
 
                    Dim l_cellSelect As New TableCell
                    Dim l_selector As New RadioButton
                    l_selector.ID = l_order.OrderHeader.OrderHeaderId.ToString
                    l_selector.GroupName = ORDER_SELECTION
                    l_cellSelect.Controls.Add(l_selector)
                    detailsRow.Cells.Add(l_cellSelect)
 
                    Dim l_nameCell As TableCell = New TableCell
                    l_nameCell.Text = l_order.Customer.CustomerName
                    detailsRow.Cells.Add(l_nameCell)
 
                    Dim l_dispatchCell As TableCell = New TableCell
                    l_dispatchCell.Text = l_order.OrderHeader.DispatchNo.ToString
                    detailsRow.Cells.Add(l_dispatchCell)
 
                    Dim l_poNoCell As TableCell = New TableCell
                    l_poNoCell.Text = l_order.OrderHeader.CustPONo
                    detailsRow.Cells.Add(l_poNoCell)
 
                    Dim l_poDateCell As TableCell = New TableCell
                    l_poDateCell.Text = l_order.OrderHeader.CustPODate.ToString("dd/MM/yyyy")
                    detailsRow.Cells.Add(l_poDateCell)
 
                    'Add the new row to the table.
                    tblOrders.Rows.Add(detailsRow)
                End While