Coding Debug cheaptextbooks.com + preloader job

Hi guys, Thanks for reading. We have a few problems with cheaptextbooks.com. The coding is in need of a cleanup. Specifically, we have a bug problem with the preloader. It looks like an easy job, but it's not so easy with the other code interacting. We also have a problem with the back button after a search - basically, we lose the page info. This is an easy enough job - if you really know what you're doing. We are not looking for total perfection, just too iron out some issues. Thanks for reading!