Does not answer my problem - I need to know the nett transfers of the stock item, not just the dollar value. If the program accepted negative quantities in the invoices then these would show in the item sales history. Sounds like a small code change to allow negative amounts as valid entries????
Also, this makes life hard as I supply on consignment and bill customers their nett sales - so an invoice for a months sales might include both positive ( ie: outgoing ) sales and negative sales ( ie nett returns ) and at the moment I can only handle this as one invoice and one dollar value only credit note.