Bookstore scrape

Hi Guys-

I recently started working on a new website that needs scraping. They are wanting to scrape each book based on the term, department, course, and section. I tried walking through the steps via the proxy, but can't figure out how the dropdowns are being populated. I figured I would scrape all that information them loop it back through to get the books for each department, course, and section. Any ideas on how to proceed?

Here is the website:

http://beloit.bncollege.com/webapp/wcs/stores/servlet/TBWizardView?catal...