How to add a movie clip to the display from a class?

programming flash
1

Hi once again. I have a MainDoc class from where I can add movieclip without a problem. Is it possible though to add a movieclip from a different class i.e Backgrd. I have this Backgrd class and am trying to put a movieclip on the stage from it. package
{
import flash.display.MovieClip;
import flash.display.Stage;

public class Backgrd extends MovieClip
{
private var thebackgrd:Backgrd;
private var JanBKGD:Backgrd;

private var container:MovieClip;
private var mainStage:Stage;

public function Backgrd(container:MovieClip) : void
{
thebackgrd = new Backgrd(container);
this.container = container;
this.mainStage = container.stage;
this.addChild(thebackgrd);
//anotherMethod();
}

 public function anotherMethod():void
  {
  thebackgrd = new Backgrd(container)
  container.addChild(thebackgrd);
  //or call
  //mainStage.addChild(thebackgrd);
  }

}
}