>In my invoice form, I have a readonly field which shows invoice number. The code in the gotfocus is :
>
>

>sele inv
>nInvno=inv.invno
>repl inv.invno with inv.invno+1
>flush
>

>
>but somtimes my client end up two invoices with same invoice number. The system is used over the network. How can I stop this. Your input will appreciated.

You have to lock InvNo record, while one person save or just before to save you have to recheck for existing InvNo to lock of afew seconds record and to save
nevertheless that when you start transaction you get next invNo from DB