Hey Cooper, it seems that most of your html code is beeing outputed with PHP.
I suggest you to use CSS for that part, so you can easily work in your layout (CSS part) and in your script (PHP part).
You'll see how much better it can be ;)
I noticed in your code you didn't reference your transistional document to anything.
Try the following instead of what you have. Not sure it will work but just a quick look revealed you only had the first half of declaring your doc type definition.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">