My window ac was leaking water and ran down wall and got the plug wet. we have tried drying it out with hairdryer but when we plug it in the reset button keeps switching. do i need a new ac or can i buy a plug?

It's hard to know which one needs replacing, without testing the outlet first. Unplug the AC unit and outlet in a lamp or some other electrical appliance to see if the outlet works as it should. If does function correctly, then the problem is in the AC unit. But, buying a new power cord will probably not solve the problem. More than likely, one of the circuits or sensors in the control panel got fried, when the water got into the outlet and shorted it out. That's why the reset button n the cord won't reset.
Depending on the age of the uni, you may want to consider having it repaired, rather than replacing it. But, if it's 5 years old or older, I'd opt for replacement.

Now, lets address what caused the problem. Either the drain hole in the drip pan was clogged and or the rear of the AC unit did have enough downward tilt. The general rule of thumb is 1/4" to 1/2" rear downward tilt. This allows the water collected in the drip pan to flow to the rear of the unit and drain away thru the drain hole. Whether you repair or replace the unit, keep this in mind.

I hope I was able to help you and thanks for choosing FixYa.