services flash user

Hello all! I'm having a little trouble finding detailed resources that explain how to manage users from inside a flash interface. I have a flash app that launches independent of Drupal, meaning the user can either access the flash system through Drupal or simply launch it by visiting a direct link. I want the user to be able to either login through the Drupal site or through the flash interface, so once the user is inside flash I need the system to check:

1) Is the user already logged in?