Age verification system or software for auction site

We need a age verification process for our adult categories, such as gun and porn type categories on our auction site http://www.auctioncrazy.com. must be free for the buyers and sellers to use and integrate into our site if possible. We are using the BidFlux auction software. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Installation package that will install the software (in ready-to-run condition) on the platform(s) specified in this bid request. 3) Exclusive and complete copyrights to all work purchased. (No GPL, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site). ## Platform auction site platform is Linux user interface(buyers,sellers,admin) Win 98-WinXP