Flv detection

How can I tell when an FLV file is done playing to then perform some kind of action on my main timeline? I have a skin for the FLV file that is playing - I’m not sure if that makes a difference.

For example:

mymovie.onEnterFrame = function () {
if (movie is done playing){
_root.gotoAndPlay(“partII”);
}
}

Thanx in advance!