[ic] Customer Credit Facility - Suggestions?

[Andy Mayer]

Hi,

I need to implement a customer credit facility, whereby customers have a
credit balance that they can top up at any time using their credit
cards. Then they can shop in the store, and if they have enough credit
then they can checkout without entering their card details and their
balance is decreased. If they try and checkout without enough balance
then the system should prompt for their card details as normal.

Does anybody have any ideas, comments, suggestions or pointers that
would help in tacking the above problem?

I am particularly interested if anybody knows of existing useful code in
the foundation demo, or has tackled a similar problem themselves.

Thanks,

Andy