Jerry,

Two thoughts:

1. How important is it to have regular backups? Can you be sure someone won't neglect to log out for too long a time? If so, you should consider a separate program for backing up that runs periodically and notifies you if it's been too long since it was able to back up.

2. Do all users share the same, application-specific resource file? If so, a separate program which doesn't use that resource file can attempt to open the resource file exclusively. If it throws an error, the program must be running. Or, the same program can SET RESOURCE OFF and then try to open the resource file. If it succeeds, no one else is in the program and it's OK to backup. And, as long as the resource file is open, no one will be able to run the program. Of course, your ON ERROR routine should gracefully handle that situation.

Jim Wiggins