The lock light is on and we don't know how to reset the dishwasher?

You might try unplugging it (if you can), or flipping the circuit breaker that controls the dishwasher. This may reset it, and is easy to do.

Good Luck,
Wally H.

Most Whirlpool washers have a reset botton right along with all the wash cycle buttons. Press and hold that button for about 10 seconds.