Additonal PayPal integration with PHP

I currrently have PayPal Website Payments Pro integration on my website for selling one and only one product. I need the following work done: Requirements: 1.) Get validation to work on check-out.html. I already have a javascript file setup to do this, however it needs to be properly configured to work right. 2.) Send customer billing data from [login to view URL] to [login to view URL] so the customer can review their order. 3.) Send customer billing data from [login to view URL] to PayPal API and if successful then 4.) Send customer to [login to view URL] with order details. I already have it setup to email myself and the customer. This functionality must remain intact. 5.) Set option for sales tax when customer chooses corresponding state and add that amount to order total. Simple hardcode of %. All work needs to be done in PHP. I already have a functional integration with PayPal. All work above has to be done and work properly for 100% acceptance. NO EXCEPTIONS. All files are created you need to work with, all this project needs is some lines of PHP code and some easy javascript troubleshooting. ## Deliverables If you are unclear of any requirements, please contact me and I will fully clarify any questions you may have. This is very easy project for experienced PHP programmer. The files you will be working with are attached so you may preview the source code. All work will be done on web server and you will be given full FTP access to do your work. Any other information will be provided as needed.