Help me - play animation

Hi,
can you help me ?
I have insert a animated sprite in my project. (stop cycle animation).
I move my animation with keyboard ( tutorial fish)

for example : When I press "d" my animation go right side.
How can play/start animation when I press "d" ?
My sprite is animated man that walk. I want to see my man walking. but I don't know how to start and stop animation.

May you help me??

thk you very much,
Claudio