These are Category, ISBN, Title, Author, and Keywords. Any number of these may be entered. Search results are displayed ordering by Category, ISBN, Title, Price. All relevent information of a listing is displayed. Make an offer user enters a message.
Offer is added to database.
Admin Functionality Add Category admin enters a new name. Name is added if name is unique. Name may not have spaces. Drop Category admin enters or picks a name. Named is deleted if name exists in database.