PayPal Documentation Links In Video 1. https://www.paypal.com/cgi-bin/webscr?cmd=p/pdn/howto_checkout-outside 2. https://cms.paypal.com/us/cgi-bin/?cmd=_render-content&content_ID=develop... http://www.developphp.com In this 19th video we program the PayPal variables and button code into our cart for allowing checkout of our custom 3rd party shopping cart. Now you are selling. The E - Commerce Web Site we will be assembling is one in which all of the inventory is in a MySQL database and we offer a custom PHP cart for a unique shopping experience. Show Less >>