How do I add a dish after I have already started the dishwasher?

First, make sure the Cycle Control Knob has not passed the Light Wash position, then lift up on the door latch to stop the cycle and wait for the spray arms to stop spinning before opening the door. After adding the dish, close the door without latching it and wait 30 seconds for air inside to warm up, then press the door firmly to latch it and the dishwasher will restart from where it stopped.