Adding a preview button, please can you help me?

Hello all,
I recently purchased a website through netfirms and setup a Zen cart shop.
Basically it’s an mp3 store. I have set my products up as download only which I found simply to do (may sound lame but I’m a bit of a dummy) so now after completing that task I tried to get a preview button to work.
Now this is the part I’m stuck on I found a guide within this site on how to do it (https://www.zen-cart.com/tutorials/index.php?article=119) I tried this guide several hundred (or at least feels like it) times and I cracked.
I then saw a post saying you have to make a sub forum for that tutorial to work so I tried that and still nothing. I have done everything I have seen and still nothing. All this just for a preview song button. Like I said I am not very computer literate so it doesn’t help.
So what I’m after is someone to help me, maybe another way this would work? If it has anything to do with scripting or coding or even html writing please could you give me a “how to do it for dummies guide” please.

Any help would be much appreciated and not forgotten.

Thanks, Stuart.

Just to let everyone no i have successfuly managed to conquer this!

I'm having the same problem you had. So what did you do to fix it? Thanks