re: OT help, dishwasher. Works fine and does NOT overflow, but

It's been working for 3 yrs. I understand about the drain pipe, but would that make it "overflow" on the next cycle? Somehow it would have the same level of water in the bottom if I ran another cycle.

How does it drain at all. Also, there is a "drain" button. Light comes on, water still there after.

Screen is clean (now)