You could have a table with field that indicates if a user is logged in or not (like in a users.dbf table). Problem with that of course is if the application crashes, then the app probably won't update the table...but I'm sure there is a creative way around that...

>in the multiusers environment, I want to set an automatic backup, after the last user logout.
>the trick is every time an user logout, the program will check if there are any other users still using the program.
>the backup will run only if only one user using the program.
>
>how can I do it?
>
>thanks for the help.
>
>regards,
>
>Jerry