I have a form that sends information into a mysql database. I want users to have to pay via paypal before there information is sent into the database. Can somebody help me. The example form is on http://cordmarston.com/cash/
use PayPal’s Instant Payment Notification to update their status. Or you might configure it directly at Paypal using their return parameter
You will want to do it with IPN. Be careful as there are some security flaws if you don't do it correctly.