How does this flash movie advance the slides in the flash slidedeck?

Question

Take a video on infoq.com (like this one: http://www.infoq.com/presentations/nutter-jruby-duby-juby). If you play the movie linked above, you'll see the slide deck advance as the appropriate part in the movie is hit. If you advance it forward and back with the slider, you'll see that it triggers to the appropriate location in the slide deck.

I'm curious how this works.

Answer 1

ExternalInterface

Answer 2

I'm guessing it does this with setInterval event listener

http://www.permadi.com/tutorial/flashjscommand/