Remove attached movies!

1

I have a movie called “my.fla” in which I attach some MC’s.
I also have buttons that load swf’s in a “container”.
But when I test the buttons, the attached MC’s in “my.fla”
keep appearing before the swf loads.

I tried EVERYTHING with removeMovieClip, but I can’t get it
to work!!(The swf’s I load also have attachMovie in them)

MovieClip.prototype.attach = function(base) {
    base["content"+nr].attachMovie("shirt_"+nr, "clip"+nr, nr);
    if (nr == tot) {
        clearInterval(id);
    }
    nr++;
};
id = setInterval(attach, 400, this);

//button:
btn_1.onRelease = function() {
    loadMovie("my_1.swf", "container");
};

Can someone help me with this?

thanks!