The shift to screen determines which screen is used after a command has been completed. For the example shown, the screen named SETUP would be entered. If this entry is empty, the current screen is maintained. If this entry names a screen that does not exist, the current screen is reentered. The way missing screen names is handled simplifies interface construction since partial interfaces can be used. Errors can occur if a CLOSECREEN control attempts to shift to an unknown screen and this condition should be caught by Vensim.
