Know of any good coupon code generators?

Hey all!

Does anybody know of any good coupon code generators? I know some shopping cart services offer this, but I'm after a standalone bit of software.

Basically I want to create an order button with a text input box next to it. If the box is left blank or an incorrect code is entered, the order button goes to Clickbank product 1 order form, and is the correct code is entered, the order button goes to Clickbank product 2 order form (which is basically the same product as product 1, but with a reduced price).

Jason Anderson seems to offer something that looks just like what I am after called 'Promo Code Software', but the main drawback to that (imho) is that is it web based and on his server. I'm not saying it will happen here, but I've been caught out with similar web based software before when for whatever reason the product owner suddenly pulls the software and I'm left with an instantly disabled business. Therefore I want some kind of standalone software or script I can install at my end and retain complete control of.

Adeel Chowdhry seemed to offer something like this a few years ago called 'Coupon Generator Pro' (based on a quick search of the WF), but that appears to be long gone.

Can anyone recommend something similar?

Or is it a fairly simple thing to program in html?
(eg. IF code = TRUE
THEN go to link 1
ELSE go to link 2
That kinda thing!)
Anything other than simple html (eg. php etc) is way over my head!

It's a pity Clickbank doesn't offer something like this out of the box. A trawl though the internet suggests that people have been asking for this feature for ages.

If anyone can recommend anything, it would be huuuuuugely appreciated and I'm completely open to other similar suggestions or workarounds!

Cheers!
James