Trouble integrating into this website

I'm new to Gallery, but a client of mine really wanted it after seeing it in action on another site. Here is the link to the gallery: http://www.bearclawtaxidermy.com/gallery2/main.php.

I installed and configured it and it worked good, but didn't know enough about editing the template to make it look exactly like my client's website. So what I did was to put the content of my client's website right onto the MAIN.PHP page. Then took all the php code involving the gallery inside one of the tables.

The result looked good initially, however, it has seemed to slowly lose function. First, I noticed it having trouble getting into the site admin. I was getting errors of "The server encountered an internal error or misconfiguration and was unable to complete your request.", while a couple times trying to view the gallery itself resulted in a timeout.

Now all of a sudden images started disappearing. First just two, now every image in the gallery is not viewable.

Can anyone look at the code and maybe see if there is some problem with that? Any other ideas?

Yes, that worked. Thank you so much.