how to make a program shareware and make provisions for registering it with a key

[uandme72]

i wish to make my program shareware.
how do i program for provisioning for the registering by a key, till that the program should display a message saying it is unregistered?
the key should be unique for all the customers.

hey im a beginner at this and ive asked this question b4
go to http://www.activelock.com and download active lock 1.5 it really works

[uandme72]

i suppose that the software from activelock.com, will be external to my own code.
isnt it possible to encode the required program along with my main program.

Actually, activelock is not external, when you install the program, you will be able to go into the Custom Controls (Ctrl+T) and it should be listed as ActiveLock 1.5, and it'll be in your program.