Water continues to run into the dishwasher even when the dishwasher is not turned on.
Here are your parts
Replacement parts for GU1200XTLB models | AppliancePartsPros.com
Here is a manual which should be useful.
http://appliancejunk.com/forums/index.php?action=downloads;sa=view;down=233
Check across the water valve for 120 volts with a meter.
If there is 120 volts then the control board is probably shot.
If there is no voltage then the water valve needs replacing.