FlashGallery scaling routine

//TODO: missbehaves on rectangular images?
//http://wordpress.org/support/topic/square-images-cropped-in-fullscreen?replies=7#post-2227942
function fitToScreen(mc:MovieClip) {
    var maxHeight:Number = Stage.height-25;
    ZigoEngine.doTween (mc,"_x",0,0,"linear",0,function () {
    if(mc._height <= maxHeight && mc._width <= Stage.width){
        mc._yscale = mc._xscale = 100;
    }
    if(_scalingStrategy != _NOSCALE){
        if(mc._height < mc._width) {
            mc._width = Stage.width;
            mc._yscale = mc._xscale;
            if(_scalingStrategy == _FILL){
                if (mc._height < maxHeight) {
                    mc._height = maxHeight;
                    mc._xscale = mc._yscale;
                }
            }
        }else {
            mc._height = maxHeight;
            mc._xscale = mc._yscale;
        }
    }
    mc._x = Stage.width/2 - mc._width/2;
    mc._y = maxHeight/2 - mc._height/2;
    });
}