package {

  import flash.display.Sprite;

  import flash.text.TextField;

  import mx.controls.Button;

 

  public class Main extends Sprite {

 

  public function Main() 

  {

   var display_txt:TextField = new TextField();

   display_txt.text = "This is text";

   addChild(display_txt);

 

   var pButton:Button = new Button();

   pButton.label="This is button";

   addChild(pButton);

  }

 }

}

import mx.containers.Canvas;

...

public class Main extends Canvas {

...

}