Loading/unloading movie problem (MX)

hello,
i have a little problem (not so little for me) with laoding movies:
on the main movie, i have a button which loads a movie with
the following script:

horta.onPress = function () {
_root.createEmptyMovieClip(“container”, 1);
loadMovie(“03_horta.swf”, “container”);
container._x = 0 ;
container._y = 210 ;
}

and another button which loads:

olot.onPress = function () {
_root.createEmptyMovieClip(“container”, 2);
loadMovie(“03_montsacopa.swf”, “container”);
container._x = 0 ;
container._y = 210 ;
}

it loads the first one perfectly, the second one too, but then, i
can’t see the first one again…
i guess the problem is about levels. i tried several thing but it’s not working…

can someone help please?