I have tried to get Authorize.net scripts working on a website for simple buy now buttons on fixed prices and an option to enter an amount to pay invoices where the user inputs an amount and invoice number. All attempts have failed. The sample scripts from Authorize.net are not user friendly. I am not alone in this problem. My Google searches have displayed many requests for help with this problem. Unfortunately, no working examples can be found, only offers to pay for custom scripts.
It would be great to have a simple CC program interface to generate such scripts and paste the code into a webpage. Just type in your Authorize.net info and payment amount and let the CC magic begin. It should be fairly simple since you already have the module for the Shopping Cart program.
What do say CoffeeCup?
CoffeeCup... Yeah, they are the best!