1999 Volkswagen Passat Lights Flashing.

I have a 1999 Volkswagen Passat and last night while it was sitting in my driveway locked the park lights and turn sgnals started flashing. Every yellow light on the car was flashing. Not the headlights or the breaklights. They would flash about 10-15 times and quit for about 10 seconds and start back up again. However, when the car was unlocked they would not flash. What is wrong and what do I need to do about it?[/B]