Check the power
If the power to your house goes off for any reason, your dishwasher is going to stop mid-cycle. Check your circuit breakers to make sure the kitchen breakers haven't been tripped. If the power circuit running your dishwasher is controlled by a light switch, make sure the switch is turned on.
Check the door
A dishwasher door must be closed and latched for the dishwasher to run, and there are several dishwasher parts that can fail and shut down the appliance's operation. Make sure the door is properly latched. Inside the door latch assembly is a micro-switch that sends a message to the dishwasher that the door is latched and it's safe to fill with water. If this switch fails, replace it to get your dishwasher working again.
Check the dishwasher pump and motor assembly
If your dishwasher's pump stops working correctly, the entire appliance shuts down. If the motor fails or fails to generate enough pressure to send water throughout the whole dishwasher, you have some significant dishwasher repair ahead of you, as the entire assembly probably needs to be replaced. Find replacement parts at Sears PartsDirect.