>My first thought was that I could trap the exclusive use in the BeforeOpentables event of the DE. I have not been able to figure it out.... tia Steve

I always use a ThisForm.lExclusive property to see if I have to open my data in exclusive. I set this property to .F. for form that need to have exclusive use of the system.

In the Load() event, I have this:

IF ThisForm.lExclusive
IF NOT OpenDbf(1)
RETURN .F.
ENDIF
ENDIF

OpenDbc() is a function in my master program which will open the DBC in exclusive use. It will return .F. and show a message to the user if it can't open the DBC in exclusive mode.