Password System

I'm trying to set up a web based password system for a client using

FileMaker Pro. I already have the passwords and ID generated. What I need

to

know now is how I get it to look at the database, spawn a matching ID and

password set to the screen and then remove it from the database. The

passwords and ID are already hardcoded into the users area in the server

settings under WebStar.

I've got the database to hand off variables to the secure e-commerce

system

of the client (Hosted on another system), once the credit card is validated

then it comes back the original server and what I'd like to have happen is

that the user then gets the unique ID and password set after which that

particular pair is then removed from the database, but it places the user's

name and various information to what group the user belongs to into a

separate database.

Any help or ideas would be greatly appreciated.