MX:Controls not Work in iphone

hi friends

i make simple air application(air2.6 sdk)

<?xml version="1.0" encoding="utf-8"?>

<mx:WindowedApplication xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" title="Hello World" >

<mx:Label text="Hello World! this is Iphone Application" horizontalCenter="0" verticalCenter="0"  fontSize="30"/>

</mx:WindowedApplication>

and make a IPA file from adt  command from commandline and install it on iphone and iphone display blank screen only no message display on screen which is on mx:Label />

and then i make another one

package{

    import flash.display.Sprite;

    import flash.text.TextField;

    import flash.text.TextFormat;

    import flash.text.TextFieldAutoSize;

    public class HelloWorld extends Sprite

    {

        public function HelloWorld():void

        {

            var textField:TextField = new TextField();

            textField.text = "Hello World!";

            textField.autoSize = TextFieldAutoSize.LEFT;

            var format:TextFormat = new TextFormat();

            format.size = 48;

            textField.setTextFormat ( format );

            this.addChild( textField );

        }

    }

}

and then i make another IPA file and install in iphone so this will work perfectly

so my Question is what is problem with use of <mx:Controls />

pls help me i have lot's of controls for my iphone app