Depth Problem - Bringing Front

programming flash
1

I don’t know if there is a simple code like this:
holder.bringFront(object);

So I wrote a code:

var i:int = 0;
var b:int = 0;
var dunya:MovieClip = new MovieClip();
addChild(dunya);
//
function yarat() {
    for (i=0; i<5; i++) {
        var k:MovieClip = new MovieClip();
        k.graphics.beginFill(0xF2F2F2);
        k.graphics.lineStyle(1,0xCCCCCC);
        k.graphics.drawRect(0,0,150,100);
        k.graphics.endFill();
        k.x=i*30+50;
        k.y=i*30+50;
        k.name="k"+String(i);
        k.addEventListener(MouseEvent.CLICK,release);
        trace(k);
        dunya.addChildAt(k,i);
    }
}
function one_getir(holder:MovieClip,hedef:MovieClip) {
    var bas:int = holder.getChildIndex(DisplayObject(holder.getChildByName(hedef.name)));
    var one_gelen:MovieClip = MovieClip(holder.getChildByName(hedef.name));
    holder.setChildIndex(one_gelen,holder.numChildren-1);
    //
    for (b=bas+1; b<holder.numChildren; b++) {
        var hedef_mc:MovieClip = MovieClip(holder.getChildAt(i));
        holder.setChildIndex(hedef_mc,i-1);
    }
}
function release(e:MouseEvent) {
    trace(e.target);
    one_getir(MovieClip(dunya),MovieClip(e.target));
}
yarat();

When you test it you will see there are 5 rectangles.The object you pressed will come to front.It works but it gives error too :puzzle:

What is the problem? Or how can I solve this?