waste water getting in to dishwasher

How do I prevent waste water from getting in to the dishwasher when it is not on. I presume it is coming from the kitchen sink as they share the same outlet pipe.

DISHWASHERS CONNECTED TO SINK WASTE. I clip a dishwasher waste hose so that its highest point is just below the work top. Its connection to the waste pipe is before the trap.

WASHING MACHINE WASTE HOSE. I clip the waste hose so that its highest point is a little lower than the top of the soap tray so that water can run to waste and not flow out of soap tray if a supply solenoid valve fails.

Manufacturers Installation instructions should be studied carefully.

Magic - why didn't I think of that? I'll try that - thanks a mill.