>On a network. Everyone has their own resource file that has their userid in the file name. Unfortunately I did not forsee that some users might attempt log onto the system more than once. For various security reasons, they are not allowed to do this. But my setting of the resource file to their useridresource file gets them multiple messageboxes. the useridresource file is already being used.
>
>How can I know that a file is already being used?
>
>Brenda

In config.fpw SET RESOURCE OFF.
Very early in main.prg:

OldOnErr = ON('ERROR')
FileInUse = .F.
ON ERROR FileInUse = .T.
USE UserIDResource.dbf EXCLUSIVE
ON ERROR &OldOnErr
IF m.FileInUse
	QUIT
ENDIF
USE IN UserIDResource.dbf
SET RESOURCE TO UserIDResource.dbf
SET RESOURCE ON

HTH,
Rich.