>Hi all
>
>With FireBird as the backend I would like to count / limit the number of users using the application. The most important point will be failed computers / OS. I can always implement a table which can maintain the count but if a computer shuts down abnormally this count would go wrong and thus create support calls and irritated users. I can only access the database using and alias so I won't actually be able to access any files physically on the server.
>
>Please advise.

You can always detect if the application is running for the users marked as logged into your system from this table when the user is going to try to log in.