how to redirect paypal after payment with values? PHP

Question

I want that people will be able to insert x money into the database, so what i need is how to redirect after payment with value, by value i mean the number of the "money" that the user pay. if someone pay 20 dollars so after the he pay with paypal he will be redirect to a page that will insert 20 dollars into the database thanks you very much! and sorry for my English :)

Answer 1

To be safe at all you must use paypal's IPN. This allows you to receive a callback from paypals servers to verify that payment actually went through. If you only use the redirect from paypal to verify that payment has been made, you will be a victim of fraud almost guaranteed.

Paypal IPN:

https://developer.paypal.com/webapps/developer/docs/classic/products/instant-payment-notification/