Disable Back Button While Payment Transaction Occurs

I have an XHTML page which is called after a successful credit card payment. But when the user hits the back button, he's charged again. How can I handle the issue, by either disab

Solution 1:

Thats the wrong design. Don't try to manipulate the client from doing bad things - prevent the client from being able to do bad things.

Case in point, use a unique token for each transaction so that if the user clicks back and resubmits the transaction it will be rejected and the user can be notified that the transaction has already gone through.