Colin,

MY simple question would be... do you want to require both people to be editing the invoice? I am thinking on a sephamore locking scheme here were when a user edits an invoice (parent or child) that the invoice be flagged, eith in its table or a sepearate locking table that it is being edited.

If this is not doable, the you should wrap conflict resolution in a trigger that runs in an SQL Transaction.

>I have posted something similar to this already and received one good idea but thought a different category and approach to the question would help. Sorry for the redundancy but please bear with me.
>
>Here is the scenario:
>
>You are asked to design an Invoice Form for a client/server system (generic to any back-end).
>This Invoice Form will be a parent-child form using the Invoices table and the InvoiceItems table.
>The main validation is that only one users changes to any part of an invoice can be saved. This means that, for example, if a user modifies an invoice by adding an invoice item line, before saving to the back end, it must be determined that no changes to this invoice have been made, either to the main Invoice table of the Invoice Items table
>
>i.e. consider the following:
>
>Both User1 and User2 are modifying Invoice 111
>User1 changes the Invoice Description (parent view)
>User2 changes the Quantity of a line item (child view)
>User1 and User2 both issue TABLEUPDATE(0,'ParentView') and TABLEUPDATE(1,'ChildView')
>
>Both users changes have now been saved to the base table. This is what I'm trying to avoid. Any ideas? TIA