The script can also be tested at:

http://www.numinix.com/1pagecheckout/

I've included the credit card module to represent all the credit card processing modules. The checkout_confirmation page has been left with its default content, but this can be changed to display something like:

PROCESSING YOUR ORDER...

Once the page has fully loaded, it will forward to checkout_process. There isn't enouch time for the customer to read the checkout_confirmation page, so it's highly recommended that it be changed to display something like as above. I will probably make this an admin feature to display whatever text you want centered horizontally and vertically on the page.