Random movieclip postition

1

How do i make it so the moviclip loads at a random X when tween starts.(but keeping it inside the stage)
This is my origanl code.

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

var mc_arr = [image1,image2,image3,image4,image5];
var counter = 0;

function tweenIn(target_mc:MovieClip){

    var image1_a:Tween = new Tween(target_mc, "_alpha", Regular.easeIn, 0, 100, .5, true);
    image1_a.onMotionFinished = function() {
        setTimeout(tweenBack,100,target_mc);
    };
}

function tweenBack(target_mc:MovieClip){
    
    var image1_ab:Tween = new Tween(target_mc, "_alpha", Regular.easeIn, 100, 0, .1, true);
    image1_ab.onMotionFinished = function(){
        counter = (counter < mc_arr.length-1) ? counter+1 : 0;
        tweenIn(mc_arr[counter]);
    };
}
tweenIn(mc_arr[counter]);