Stop the looping of an array

1

How can i stop this array from looping. I just want the images to fade in once then stop after theyre done.

import mx.transitions.Tween;
import mx.transitions.easing.*;

var mc_arr = [num_mc1,num_mc2,num_mc3];
var counter = 0;

function tweenIn(target_mc:MovieClip){

var image1_a:Tween = new Tween(target_mc, "_alpha", Regular.easeIn, 0, 100, 1, true);
image1_a.onMotionFinished = function() {
  counter = (counter < mc_arr.length-1) ? counter+1 : 0;
    tweenIn(mc_arr[counter]);
};

}
tweenIn(mc_arr[counter]);