You would need a third party ecommerce shopping cart software, and use a
secure certificate such as verisign installed on the server. You would need
to contact your host to see what they support.
do you mean you want to do a site to accept credit card payments......?
There's not much in FP that can do that outright (perhaps some Microsoft Passport
third-party ecommerce thing that you need to sign up for......but in the end if
you want a custom product, you'd need custom scripting, a secure server
(https://) with valid security certificate etc.
The easiest way is probably to find a product (a shopping cart/checkout product)
that supports PayPal, and use Paypal to do the CC processing, but use the
shopping cart/checkout/catalogue for your product listings.