Discount/Coupon management

We currently have a classified ads system using Shop-Script PRO Shopping cart. Our website is [login to view URL] (Sorry, we do have the spanish version only) We would like to create a complete discount module with at least the following features: > - Coupons with limit use of times > - Expiration date > - % desct > - With option to manage/maintain de coupon table > - Verify who uses the coupon > - Coupon SHOULD be attched to one single person This new module will be attached to the current application. So, when users place and ad, the system will automatically search if Questions: (1) Can you please show your portfolio before bidding? (2) Any demo or website that you have created related to discounts and coupon? (3) Do you have a degree in Computers or any programming certification?