Custom Fields system in PHP

This is a job for an PHP expert. This is not a simple project that you may do in an hour! I have made PHP software for ten years, and even I think this is a bit challenging. Improve the Extra Fields functionality in PHP Classifieds. Extra fields is custom fields like an extra dropdown menu that the ad submitter get when he creates a new ad, or even changing his personal user information and during registration. Every answer to a Question is saved in a database. So it is very flexible rigth now. You can also search on extrafields. The extra fields system is creating cache files in order to save resources, specially when using extra fields in lisings. The extra fields options, questions etc. is put out to Smarty. You may also re-arrange questions. You can download the script and test: <[login to view URL]> You can see the db structure for the extra fields part here: [[login to view URL] ][1]Description of extra fields: <[login to view URL]> <[login to view URL]> Main focus: 1. Keep the current db structure as it is db normalized. 2. Find a way to sort on the values of the extra fields in listings (like sort on a extra field named Price). 3. Optimize and make it easier to use/implement extra fields for a programmer, specially for searching. 4. Speed is fatal with this project. There is ways to do this by quering the db a lot more, but I´m not interested in lower performance. 5. Extra fields system is used on ads, users, on search, in the ad itself (display) and in the info about the ad seller. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform Linux, Windows, all major browsers. PHP4/PHP5 and MySql4