Duplex (double-sided) printing

Can somebody tell me how to print duplex. I want to print a range of invoices in duplex but when I started a new customer a next (new) paper should be taken. But as long as it’s the same customer’s invoice the report should be printed duplex. How can I tell the printer that each new customer’s first page started with pageno 1.


I have no problem printing single invoice duplex, the problem comes if I want to print a range of invoices. I’m trying to use MOD 2 and NEWPAGE but it doesn’t work correctly yet.