Countdown timer

Hi:

I'm trying to add a countdown timer (counting down from 5:00 minutes, by 1 second.) I found a few tutorials online, but couldn't make them work. I don't think it will let me add a web address here, so I'll describe... I used one called "Edge Animate Tutorial: Countdown using API". the other was "Creating End Of The World Timer with Edge Animate"

I painstakinlgy recreated the steps. But my numbers did not count down when I hit play. Basically, nothing happened...

I could just animate each number, but for 5 minutes by seconds that would be 300 actions. I'm hoping someone who's good with code knows how to do this with js.

Thanks!