How do you make a re-settable countdown? (resets on trigger)

This is what i want to do:

Push button, 10 second countdown starts to trigger an entity.

Push button again, countdown resets (starts over).

EG:

(Push button)....10...9....8....7....6 (Push button again) 10....9....8....

If nothing is pushed, countdown goes to 0 then triggers an entity. Then does nothing and waits for original button to be pushed to start countdown agian.