Implementation of serial number

[Ton Kuypers]

A very good day to you all!

I am in the progress of finalising a small commercial program for the  
graphic industry: select one or more PDF files and have Adobe  
InDesign put them in the correct location and order to create  
impositions.

Everything is working the way it should, so now I am thinking to add  
a serial number to the program, but have nu idea where to start...
I cannot rely on an online database with predefined serial numbers.  
People interested in the program can pay through PayPal on our  
website and then download the program.

I don't mind sending them a serial number manually when I receive the  
payment, but how do I create this serialnumber without every-time  
having to create a new stand-alone for this serial?
Has anyone an idea how to set this up?

Any ideas are welcome, many thanks in advance!


Warm regards,

Ton Kuypers
Digital Media Partners bvba
Tel. +32 (0)477 / 739 530
Fax +32 (0)14 / 71 03 04
http://www.dmp-int.com