Help on changing Scenes from a (non-document) class

programming flash
1

Hey Folks - I have a non-document class that I want to put in charge of changing scenes when some conditions are met.

First things first, I need to figure out how to change scenes!

Here’s my code:

package classes {
    
    import flash.display.MovieClip;
    import flash.display.Stage;
    
    public class SceneMaster extends MovieClip {
        
        public function SceneMaster(stg:Stage):void {
            
            trace("done", stg)
            gotoAndPlay(1, "Lobby");
        }
    }
}

Here’s the error I’m getting:

ArgumentError: Error #2108: Scene Lobby was not found.
at flash.display::MovieClip/gotoAndPlay()
at classes::SceneMaster()
at GameMaster()

I’ve tried accessing it like this

stg.gotoAndPlay(1, "Lobby");

but I get this error:

1061: Call to a possibly undefined method gotoAndPlay through a reference with static type flash.display:Stage.

Anyone have any ideas on how to do this?