I am working on a simple shopping cart. The system is finished and I'm having troubles with PayPal.
The code is taken from the PayPal website and I can't find anything wrong in there. I enabled "Instant Payment Notification" but after I pay and get back to the website, it says the payment has not been validated. I want to use the IPN to make it at least a little secure.
The website is coded in php. All PayPal scripts use php as well.
This is a very quick job for a few minutes, so I guess something around $10 would be appropriate.