In april this year you posted this reply to at tread regarding User Exits in billing process:
Re: user exit/customer exit/BADI at the time /after saving SD invoice
Posted: Apr 13, 2005 10:00 AM Reply E-mail this post
I'm trying to check at the line item level for zero values items. If found, I would like to flag it as error in the billing log and the user shouldn't be able to save the invoice. I've no idea if I could implement this using copy requirement (VOFM). Sorry to the original poster for hijacking this thread.
Have you solved your problem, because I have a similar problem, and I would like to know how you fixed your problem.