Hi Joey,
The answer to your question is that it's done using Javascript and some "encrypted" (and I use that term very loosely) that creates a frameset to frame the new page in.
I've edited/broken down the code in spots for you so that you can see exactly how it's done, step by step (as much as I could anyway). You'll see the Clickbank URL as well.
http://www.walkonmypath.com/javascript-redirect.html
Now...this is NOT something I would recommend you do for three reasons:
1) It's incredibly misleading to the end user. This is the big reason...they don't know they're on an affiliate website. travis24 is just trying to cheat that.
2) The code is "crackable" (I just did it and it took me about 45 minutes, mostly because I forgot how to do something).
3) Pages contained within framesets tend to confuse users who pay attention to the address bar (it's also a ***** from a bookmarking standpoint.)
From the looks of the sites you have in your signature, you're trying to get rich quick. I'll save you more time and money than any of the scamlords you're working on behalf of ever would and tell you this:
Millions before you have tried thin affiliate marketing (affiliate marketing of absolutely screw all.)
Millions before you have wasted a lot of time doing it and have failed miserably.
Almost no one has succeeded with this stuff (the ones that do succeed are the ones that come up with the scams in the first place.)
You will make little to no money.
You will get pissed off.
You will wonder how everyone else is doing it and you're not (they're not either.)
The only thing that has ever worked online from a commercial point of view is the same thing that works offline: unique, original stuff sold by people who actually know what they're talking about. Get off the path you're on. It will lead you nowhere.