People apply to our services through a web form, and all the info is stored in infusion. What I would like to do is allow them to choose a username and password, which allows them to log in to our site and access various services.

To do this, i'll need to connect with infusion through the API and, and check that a username is available before submitting the form through to infusion for real. I'll probably have to do a real time check using AJAX as they type in a username.

If anyone has any experiences in this area that could help, i'd love to hear. Becuase I really have no idea where I'm going to start!