Dishes don't get clean, dirty

you have a blocked drain pipe. begin by snaking out the drain and disposal at the sink level. then run the dishwasher empty to see if it is draining properly. if you still have water sitting in the bottom of the dishwasher remove the kick panel on the front near the floor. Then you will see the drain hose and the small pump that drains the dishwasher. Chances are if you get this far, there is debris caught in the pump, like a piece of glass or bone. good luck with it.

Sounds like the main drain is stopped up.The problem is that the water can not drain from the dish machine,because of a blocked main drain .The drain is blocked under the disposal,This may be a bigger job removing the disposal.Is water standing in the disposal?Most likely the disposal will have to be removed to access the main drain under the disposal.Once the drain is clear,run the dishwasher empty,with about a cup of bleach,If you have a choice on hot,warm,or cold water on the dishwasher,choose the hot selection.This will clean,and sanitize the machine.I hope I shed some light on the problem at hand,if I did,please let us know thank you.