When you are using a simple "Buy Now" Paypal button & you specify a "return" page, how can you tell the result of the transaction? (Good or Bad).
As best I can tell, from testing, there is no "bad" because PayPal will NEVER let you finish unless you put in valid info. You are stuck until you x out that page. Seems VERY unprofessional.
Is there a parameter (hidden form field) that let's you allow Cancel? So the customer is not left in limbo?