Serial Do Nerovision Express 3.1.0.25 I Purchased IWork'08 But I Don't Have A Serial Number. How Do I Get One Without Having To Pay Additional?

I purchased iWork'08 but I don't have a serial number. How do I get one without having to pay additional? - serial do nerovision express 3.1.0.25

I already paid $ 80 for the software and pay no more ..... HELP?