[F8] How can I target this movieClip that I loaded onto the stage?

programming flash
1

I’m trying to target a .swf that I loaded into a movie clip (mc_container) but it seems like I’m missing something. Can you take a look and see where I went wrong?

mc_container.loadMovie("mc_photoSwap.swf");

//homepage Animation Swap Images
function photoSwapAni(){
    switch(random(3)){
        case 0:
        _root.mc_container.gotoAndPlay("ani_1");
        trace("case 0");
        break;
        case 1:
        _root.mc_container.gotoAndStop(50);
        trace("case 1");
        break;
        case 2:
        _root.mc_container.gotoAndStop(100);
        trace("case 2");
        break;
    }
}
var intervalID:Number = setInterval(photoSwapAni, 2000);

Also I see I’m going to have an issue with the random part because it could call the same animation twice or more times in a row. Should I ad some sort of if statement or is there a better way to do this random part of the code?