Need script to randomly fade mcs?

[cancerinform]

chechMc = setInterval (nextMC, 500);
fadeturn = false;
myRandomMcs = new Array (6, 7, 8, 9, 10, 11);
function nextMc ()
{
    nextMcToFade = myRandomMcs.splice (random (myRandomMcs.length), 1);
    trace (["mc_" + nextMcToFade]);
    var myMc:String = "mc_" + nextMcToFade;
    fadeClips (myMc);
    if (nextMcToFade.length == isNaN (0))
    {
        trace ("Empty array");
        //this is where I need the alternating tricker each time to set fadeturn true or false
        myRandomMcs.push (6, 7, 8, 9, 10, 11);
        nextMcToFade = myRandomMcs.splice (random (myRandomMcs.length), 1);
    }
}
function fadeClips (myMc)
{
    var mc:MovieClip = eval (myMc);
    this.onEnterFrame = function ()
    {
        if (fadeturn == true)
        {
            //do fade up
            mc._alpha += 3;
        }
        if (fadeturn == false)
        {
            mc._alpha -= 3;
            if (mc._alpha <= 0)
            {
                delete this.onEnterFrame;
                nextMc ();
            }
        }
    };
}
nextMc ();