Disable autostart on an html 5 canvas?

I have a loop animation with a "Start" and "Stop" button.

What I want is for the animation to open up and not start playing until they push start but then keep looping until they push stop.

I have used the stop function on frame 1 but then it doesn't loop.  How can I have it not autoplay, but also loop unless the user clicks stop?

(html 5 btw)

Thank you!