Unload a movie clip as the play head jumps to another frame

Hey everyone:

The movie clip is called “theScene” and I have it created on Frame 60 of a movie clip when a button triggers the playhead to jump and stop at Frame 60. However, upon leaving that frame, it will not disappear, so I want to unload it upon leaving that frame.

I put in the following code across all frames of the movie clip in its own layer:

 
if (this._currentframe !=60)
    {
        theScene.unloadMovie();
    }

This does infact unload the movie if I put it in the keyframe with the code that creates it (on Frame 60), but it will not unload it upon moving the play head to another Frame, i.e. clicking a button to jump that movie clip to Frame 50, 70, 100… whatever.

I added a trace(this._currentframe), however, it will only trace Frame 1, and never runs again, how do I get it to run everytime the playhead moves?

Thanks,
Adam