>If I want to get exclusive use of a dbf() on the network Can I simply test for someone using it first by issuing " ?flock()" so that I won't have to resort to an error routine?

You can still get a file lock on a table that is open by another user as long as the other user has no records locked. While it is a good first clue to exclusivity, flock is not a guarantee that you can then open the table exclusively. Try:

lcOldError = on('error')
llOpen = .t.
on error llOpen = .f.
use mytable excl
on error &lcOldError
if !llOpen
   return .f.
endif