AS3: Dynamische Pfade?

function LoadAndDisplayNavigation() {


    // Navigations-Container erstellen ("nav_mc")
    var nav_mc:MovieClip = new MovieClip();
    nav_mc.name = "nav_mc";
    stage.addChild(nav_mc);


    // XML laden
    var loader:URLLoader = new URLLoader(); 
    loader.addEventListener(Event.COMPLETE, loadXML); 
    loader.load(new URLRequest("menu.xml")); 

    // Menüpunkte auslesen und anzeigen
    function loadXML(e:Event):void
    {

        XML.ignoreWhitespace = true;
        var navbuttons:XML = new XML(e.target.data);
        var navbuttons_count:Number = navbuttons.btn.length();

        var i:Number;
        for(i = 0; i < navbuttons_count; i++)
        {
            var mc:navbtn_mc = new navbtn_mc();
            nav_mc.addChild(mc);
            mc.name = "navbtn" + i + "_mc";
            mc.txt.text = navbuttons.btn[i].text();
        }
        trace(nav_mc.name);
        trace(mc.name);
        trace(nav_mc.navbtn1_mc.name); // error

    }


}


LoadAndDisplayNavigation();