Is there any way of disabling or removing the 'X' in the upper right corner? I would like to control the "ending" within my program instead of allowing users to stop by using the "X". My main screen is left on and hidden in the background. By hitting the "X" it brings users back to the main screen, but does not close all of the tables. If someone immediately restarts the program before turning it off fully and restarting, an error message appears saying that some tables are already in use.