Swap Depth

programming flash
1

i have 3 button that load 3 images, i have 2 movieClips when first button is clicked it loads 1 movieClip with the image and the 2nd button clicked once loaded would fade out the first(top) mc . and it would just keep swaping based on if its loaded.

function swapPhoto(newHero) {
    var currHero = newHero;
    if (newHero == currHero) {
        _root.picture.loadMovie(newHero);
        _root.picture.swapDepths(_root.picture2);
        trace("D1");
    } else {
        _root.picture.loadMovie(currHero);
        _root.picture2.swapDepths(_root.picture);
        trace("D2");
    }
}