1. Turn off the water supply to the dishwasher.
2. Open the dishwasher door.
3. Locate the reset button on the inside of the dishwasher, near the bottom of the door.
4. Press and hold the reset button for at least 10 seconds.
5. Close the dishwasher door.
6. Turn on the water supply to the dishwasher.
7. Start the dishwasher.
If this doesn't reset the dishwasher, you can try unplugging it for a few minutes. Here are the additional steps:
Locate the power cord for the dishwasher.
Unplug the power cord from the outlet.
Wait for at least 15 minutes.
Plug the power cord back into the outlet.
Turn on the dishwasher.
If neither of these methods works, you will need to call a qualified repairman.