Dishwasher not pumping water. Hi, My dishwasher is not pumping water through the rotating arms. I

Question

Hi, My dishwasher is not pumping water through the rotating arms. I have been noticing that the dishes were coming out dirty and the detergent tablet falls to the bottom of the machine. I have put the machine on just a rinse cycle. (someone told me this might clear up the problem.) I have opened the door and press the little switch to activate the machine and can see that the water is getting poured into the washer via a side inlet. Water is at the bottom of the washer and the heating element turns on. Water gets pumped out and no water is pumped into the swinging arm. Help!!Thanks, Matt