validating if the user really paid

[kalo]

I have realized that if you login as a user you are able to load checkout_success.php without even purchasing any goods. Does any one validate if the answer from PayPal or any other credit card validator is positive (The credit card was charged)?

I need to load another page once I am sure that the user was charged and I would like to use checkout_success.php as a trigger to this other page.

[deviantla]

Well one way to validate if someone has truly paid would be to log into your PayPal interface and verify the transfer of funds. It would seem to me that if a transaction took place then this would be the place to make sure. I would not send anything out to anyone until making sure I had the funds before they had the goods.

Also, I noticed as well that it is true you can load the checkout_success.php from your browser without actually checking out. However if you also notice, if an item is in your cart while laoding this page, it remains in the cart. I son't think this would be a major issue.