i only want all user to open db frontend one at a time. how would you do this?

for example, if user have db open and open db again. the second attempt will force user to close second application.

thanks to all in advance.

Have the user open the database "exclusive". To do this, open the database, go to Tools in Access main menu, the choose Options. From here go to the Advanced tab, then in the Default Open Mode, change from Shared to Exclusive. Exclusive Mode will not allow other users to open the database will you have it open.

HTH
RDH