changing my index.php

Hi

I'm using dreamweaver. I'd like to change my guestbook to reflect the look of my website. I got close. (www.halfpastnine.com/advancedquestbook) but..
The guestbook no longer works when you post a comment.

Are there instructions on how to do this? I'm not a php programer, but I know enought to take what's there and tweek it.

When I try to open up the original index.php in my guestbook in Dreamweaver, I get nothing. However, if I cut and paste the page info as a php document I can see it. ???

Any advice?

Thanks!