Return User level via Javascript

Jason,
A long time ago I had a s2 code for Flash Builder in action script (which I need to do now from Javascript from a webapp) that I could send a username and password to verify the user and return the subscription level. If I remember right it was in the s2_hack and I passed the following line:

www.domain.com/s2_user_pass_ok=1234-something-secret-1234&s2_username=username&s2_password=password

If I remember it would return the level, 0 for free, and -1 if not registered. I tried searching the forum for it, but it was a long time ago. If this is still possible can you let me know how.

Thanks a bunch.