I am trying to have my Windows application run the backup for the user,
by executing GBAK invisibly with the correct arguments.

The problem comes if they are backing up to diskettes, and the backup
does not fit on one diskette. The GBAK program doesn't just fail with
an error (which I could deal with), but rather it hangs, prompting the
user for another destination.

There doesn't seem to be any command-line argument I can give to GBAK
to modify this behaviour. I know I can give multiple targets, but since
I don't know how big the backup will be, I can't see what I would put
there. Plus, I can't get response back to prompt for a 2nd diskette,
and just running it in a Command Prompt window that the users see seems
to be a bad idea, because my users aren't technical, and the prompt
that GBAK puts out for another target won't be clear to them.

Any bright ideas? Thanks.