createEmptyMovieClip and removing them

Hi guys,
can someone explain why I can’t get this to work

i have some buttons on level 4 of my flash presentation, each button unloads then loads a different swf into level 3.

I have a swf which I need to position using createEmptyMovieClip, I can only do it this way because the interaction of this movie relies on the co-ordinates of the mouse, so rather than load it into a new level I am using an emptyMovieclip to hold the swf in the correct screen position on level 4.

It loads perfectly but, when I try and remove this clip once another button is pressed, it stays on the screen, with the new movies loading directly on top.

This is the code on the button which loads the swf

on(press, release){
unloadMovie(3);
this.createEmptyMovieClip(“empty_mc”, this.getNextHighestDepth());
empty_mc.loadMovie(“dancing.swf”);
empty_mc._x = -420;
empty_mc._y = -200.5;
}

and this is the code im using on the other buttons to try and remove the clip.

on(press, release){
unloadMovie(3);
empty_mc.unloadClip(“dancing.swf”,4);
loadMovieNum(“webcam.swf”,3);
}
/i have tried empty_mc.unloadClip(“dancing.swf”);/

Im really confused, I have also tried removing the clip by using

_root[“empty_mc”].removeMovieClip();

any help or a pointer to another thread / tutorial on this would be great
I hope that made sense
:puzzled: