I need to pass a variable to PayPal when someone checks out and have it pass it back when the payment is completed. Basically I need to direct the user to PayPal to pay, then, after they pay have PayPal tell me in the return url who paid so I can update their subscription in the database.
Right now, after someone registers they are directed to https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=EF3UGS6GMWP56 and then after they pay, they are directed to https://culturehog.com/success
I need something more like: https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=EF3UGS6GMWP56?USER=467
and: https://culturehog.com/success?USER=467
Then I can have the PHP update user 467 in the database to "paid."
Does anyone have any experience with this? :/
https://culturehog.com/success?USER=467
is not secure, someone could brute force all your users to be paid very easily. – user3783243