Dear All,

In order to control each User ID can only be used by one user, my program save the UserID and update to the table while the user logging in. The record will be deleted when the user log out from the main screen.

I encounter the problem if the system is interrupted by power failure or illegal operation... which is improper shutdown without exit from the main screen. The User Id record still in my table. In order to delete this record, I have to access to the database and delete this record before I can use the similar user Id.

From the above problem, is there any other methods which I can used to control each user id can only be used by one person? Or delete the record in the table if the program is not quit from the main screen (Because my delete procedure is code in main screen - destroy event)

Thank you very much for your advise and help.


Regards,
Miss Thian