Water is leaking from under the dishwasher when sink water is running. I pulled out the dishwasher and there is no leak from there. I ran the water and watched the area as I ran the sink water. Water started coming from the floor under the wall bhind the dishwasher. What should I do next

Sounds like you have a leak in the kitchen sink drain pipe in the wall.

Posted right on top of you Harold
If you have a older house with cast iron drainage and copper drain arms I can tell you exactly what happened because I had the same thing happen to me.
The copper drain line inside the wall sprung a leak and now your sink's drain all over your floor.
If you're handy this can be a job for the home owner. It will involve opening up the wall and replacing the old ate up copper with PVC. Are you up to that? Let me know, Tom