Checking if movie is loaded?

Hi Guys, need some assistance her. I have a project that currently is near comlpetion but I have just had to ad an intro movie that plays while the user selects from a menu on the left. There are two menus in play here, initial menu then a sub menu then another final menu. these are on 3 frames respectively. What I need to do is load the into movie into a placeholder on Frame 1, then when the user clicks to go to frame 2 to the next menu, the intro movie keeps playing rather than reloading from the beginning. Then I need to be able to reload the intro file from the beginning if the user click back to frame 2 from frame 3 of the main timeline. So I need some code to

A: Initially load the external intro.swf into container (Already got this bit)

B: Check to see if the intro.swf is loaded and if so leave it running and not reload it.

C: Check to see if the intro.swf is unloaded and if so, load it!

I’m currently trying this code but to no avail.

Frame 1 (Main Timeline)
loadMovie(“swf\INTRO\Intro.swf”,"_root.main_container");
_root.currentmovie==“Intro”;

Frame 2 (Main Timeline)
if(_root.currentmovie==“Intro”){
// Do nothing
}
else{
loadMovie(“swf\INTRO\Intro.swf”,"_root.main_container");
}

Frame 3 (Main Timeline)
unloadMovie(_root.main_container);
_root.currentmovie="";

Any suggestions would be helpful as I’m running out of time on this.

P.S. I have three instances of the container - 1 on each frame.

Andy