So how can we generate an invoice copy for already Billed document?
enter the required output manually, then you can generate the print.
Even for proforma invoice it is necessary to maintain output determination procedure?
It is not required to maintain the separate procedure for Proforma invoice, you can assign the Proforma invoice output in the same output procedure which you are using for billing document.
Since you have mentioned that no output records maintained, better maintain so that it will be determined automatically during document creation.
thanks,
Srinu.