#2007: parameter must be not null error

Hi.
I need some help.
I have this source code.
My problem is that i get the #2007: parameter must be not null error whene I add the _label1, _label2, _label3 childs. It is at the end of this source code.


package com.roytanck.photowidget
{
	import flash.display.Sprite;
	import flash.display.MovieClip;
	import flash.display.BlendMode;
	import flash.events.*;
	import flash.events.MouseEvent;
	import flash.net.navigateToURL;
	import flash.net.URLRequest;
	import flash.display.Graphics;
	import flash.geom.ColorTransform;
	import flash.display.Loader;
	import flash.filters.BitmapFilter;
	import flash.filters.BitmapFilterQuality;
	import flash.filters.DropShadowFilter;
	import flash.filters.BlurFilter;
	import flash.text.TextField;
	import flash.text.Font;
	import flash.text.TextFormat;
	import flash.text.TextFieldType;
	import flash.filters.GlowFilter;

		
	
	
	public class Thumb extends Sprite {
		
		private var _label1:TextField;
		private var _label2:TextField;
		private var _label3:TextField;
		private var _arhat:Sprite;
		private var _szamhat:Sprite;
		

		
		private var _back:Sprite;
		private var _mask:Sprite;
		private var _node:XML;
		private var _cx:Number;
		private var _cy:Number;
		private var _cz:Number;
		private var _holder:MovieClip;
		
		private var _img:Loader;
		
				
		public function Thumb( node:XML ){
			_node = node;
			
			
			// create a holder mc
			_holder = new MovieClip();
			addChild(_holder);
			
			

					
			
			var sorszam:String = new String (_node["@sorsz"]);
			var _label1:TextField = this.createTextField(-47.5, -45.5, 20, 20);
            _label1.text = sorszam;
            _label1.selectable = false;
            _label1.textColor = 0xFFFFFF;
			
			var _label1TextFormat = new TextFormat();
            _label1TextFormat.bold = true;
			_label1TextFormat.size = 9;
			_label1TextFormat.font = "Lucida Sans Unicode";
			_label1TextFormat.align = "center";
			_label1TextFormat.tabStops;
			_label1.setTextFormat(_label1TextFormat);
			

            var ajnev:String = new String (_node["@nev"]);
			var _label2:TextField = createTextField(-35.5, -35.5, 70, 70);
			//ajnev=ajnev.toUpperCase();
			_label2.text = ajnev;
			_label2.selectable = false;
			//_label2.embedFonts = false;
			_label2.filters=[new BlurFilter(1, 0, 10)];
			//_label2.blendMode = BlendMode.SUBTRACT;
			_label2.multiline=true;
			//_label2.type = TextFieldType.StaticText;
			_label2.wordWrap = true;
			_label2.textColor = 0x0099FF;
			_label2.antiAliasType = "advanced";
			
					
			
			var _label2TextFormat = new TextFormat();
            _label2TextFormat.bold = true;
			_label2TextFormat.size = 6;
			_label2TextFormat.font = "Lucida Sans Unicode";
			_label2TextFormat.align = "center";
			_label2TextFormat.tabStops;
			_label2.setTextFormat(_label2TextFormat);
			
			
			var filter:GlowFilter = new GlowFilter(0xFFFFFF, 100, 2, 2, 10, 1,false,false);
            var filterss:Array = new Array();
            filterss.push(filter);
            _label2.filters = filterss;

           
 		    		
			var ar:String = new String (_node["@ar"]) + " Ft.";
			var _label3:TextField = createTextField(-37.5, 23, 75, 15);
			_label3.text = ar;
			_label3.selectable = false;
			_label3.textColor = 0xF74300;
			_label3.antiAliasType = "advanced";
			
			
			var _label3TextFormat = new TextFormat();
            _label3TextFormat.bold = true;
			_label3TextFormat.size = 7;
			_label3TextFormat.font = "Lucida Sans Unicode";
			_label3TextFormat.align = "right";
			_label3TextFormat.tabStops;
			_label3.setTextFormat(_label3TextFormat);
			
			
			_arhat = new Sprite();
			_arhat.graphics.beginFill(0xFFFFFF, 0.6);
			_arhat.graphics.drawRect( -37.5, 25, 75, 10 );
			_arhat.graphics.endFill();
			
			
			_szamhat = new Sprite();
			[Embed(source='test.jpg')]

			_szamhat.graphics.beginFill(0xFF9933, 1);
			_szamhat.graphics.drawCircle(-37.5, -37.5, 8);
			_szamhat.graphics.endFill();
			
			
				
			
			

			
			
			// get and display the thumbnail image
			_img = new Loader();
			var urlReq:URLRequest = new URLRequest( node.toString() );
			_img.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, errorHandler);
			_img.contentLoaderInfo.addEventListener(Event.COMPLETE, completeHandler);
			_img.load(urlReq);
			_holder.addChild(_img);// kep kivéve
			// events
			this.buttonMode = true;
			addEventListener(MouseEvent.CLICK, clickHandler);
			
           	
			// hide tag for now while loading
			this.visible = true;
		}

		
		    private function createTextField(x:Number, y:Number, width:Number, height:Number):TextField {
            var result:TextField = new TextField();
            result.x = x; result.y = y;
            result.width = width; result.height = height;
			addChild(result);
            return result;
									
        }
		
		


        private function clickHandler( e:MouseEvent ):void {
			var request:URLRequest = new URLRequest( _node["@href"] );
			
			var targetFrame:String = ( _node["@target"] == undefined ) ? "_self" : _node["@target"];
			navigateToURL( request, targetFrame );
		}
		
		private function errorHandler( e:IOErrorEvent ){
			trace("ioErrorHandler: "+e.toString() );
		}
		
		private function completeHandler( e:Event ){
			// scale image
			if( _img.width > _img.height ){
				_img.height = 75;
				_img.scaleX = _img.scaleY;
			} else {
				_img.width = 75;
				_img.scaleY = _img.scaleX;
			}
			_img.x = -_img.width/2;
			_img.y = -_img.height/2;
			// draw mask
			_mask = new Sprite();
			_mask.graphics.beginFill(0xffffff, 1);
			_mask.graphics.drawRect( -37.5, -37.5, 75, 75 );
			_mask.graphics.endFill();
			_holder.addChildAt(_mask,0);
			
			
			
			_img.mask = _mask;
			// create the back
			_back = new Sprite();
			// apply drop shadow filter
			var filter:BitmapFilter = new DropShadowFilter( 3, 45, 0, 0.4, 6, 6, 1, BitmapFilterQuality.MEDIUM );
			var myFilters:Array = new Array();
			myFilters.push(filter);
			filters = myFilters;
			// draw background
			_back.graphics.beginFill(0xffffff, 1);
			_back.graphics.drawRect( -41.5, -41.5, 83, 83 );
			_back.graphics.endFill();
			_holder.addChildAt(_back,1);
			
			
			_holder.addChildAt(_szamhat,3);
			_holder.addChildAt(_arhat,4);
			
			_holder.addChildAt(_label1,6);
			_holder.addChildAt(_label2,7);
			_holder.addChildAt(_label3,8);
			
			
			//swapChildren(temp, target);
			
			// add a little randomness
			this.rotation = 10 - Math.random()*20;
			// set button mode
			this.buttonMode = true;
			// show image			
			this.visible = true;
			//add text
						
			
		}

		// setters and getters
		public function set cx( n:Number ){ _cx = n }
		public function get cx():Number { return _cx; }
		public function set cy( n:Number ){ _cy = n }
		public function get cy():Number { return _cy; }
		public function set cz( n:Number ){ _cz = n }
		public function get cz():Number { return _cz; }

	}

}

10x.