1. Sales Invoice: Every time you print this document there is a field on the Sales Invoice Header that is updated (No. Printed) it is a integer field that is incremented by 1. If you want to limit it then put a code that will trow an error when the value of No. Printed is not 0.
2. Purchase Invoice: Every time you print this document there is a field on the Purch. Inv. Header that is updated (No. Printed) it is a integer field that is incremented by 1. If you want to limit it then put a code that will throw an error when the value of No. Printed is not 0.
