Unload movie w/ JavaScript?

Only after completing a pop-in window + Flash video setup did I realize that Explorer refuses to unload the video after the user closes the pop-in window:
http://angledend.com/clients/mse/variety_bands_orchestras.html (click any of the right-hand links - when you start the video, then click the “close” link, the video and sound keep playing in the background)

I’m having the damnedest time finding a work-around for this. It isn’t feasible to move the “close” function into the Flash movie with an FScommand because the close function is pop-in window-specific (i.e., each close function is unique). What I’m hoping is that there’s some way of unloading the “level 0” movie from the player using JavaScript in the close window link, but I haven’t found anything to that effect on the web after hours of searching.

I’m also open to other ideas. Does anyone have any, or know how I can kill that video using JavaScript?

FWIW, I don’t really write JS or AS - I’m pretty good at working with them to make them do what I need (normally), but can’t write any of it from scratch.