flash actionscript: I am using Flash MX.

The set up...

I have a main swf file that I am loading and unloading other external swf
files into a blank MC for the placement. What I am having trouble with is
loading and unloading a swf to the blanc MC on the main stage from inside a MC
that has buttons. It is almost there though. The buttons load the external
swf file, but it loads it into the MC that the buttons are in. The code fopr
each button I am using on the actions layer of the MC that holds my buttons is:

counterTopCatBut.onRelease = function () {
unloadMovie("root.emptyMC");
loadMovie("countertopgal.swf", root.emptyMC)
_root.galleryCats._visible = false
}

galeryCats is the lable of the MC that is on the main stage that holds the
buttons.

The reason I am doing it this way is because I have 4 buttons on the bottom of
the main stage that load the different external swf files. My gallery button,
when released, makes the galleryCats MC visible which has 4 more buttons inside
for the differrent catagories. These 4 buttons that are now visible are inside
the galleryCats MC that has the above code on the MC actions Layer. I also was
trying to set the galleryCats MC visiblility to false when one of the buttons
inside the galleryCats MC is clicked.

My questing is:
How do I load and unload external swf files to and from an empty MC, on the
main timeline, from buttons that are inside a MC that are also on the main
timeline?

Thanks for any help

it seems like theres a whole bunch of us with issues swirling around dynamically loading clips, masks, layers, levels, etc.