Unload movie script

I am having trouble with a movie clip that once it loads the external swf, the swf appears on every scene in my movie.

here is the script i used to create the empty movie clip:

but.onPress = function() {
_root.createEmptyMovieClip(“container”, 1);
loadMovie(“Untitled-3.swf”, “container”);
container._x = 400;
container._y = 300;

if anyone can help me to have it unload when i try to go to another scene or “page” on my site.