Communicating between linked classes

Question

I have been struggling with what seems to be simple concept in ActionScript 3.0 - how to communicate between classes. I have a very simple experiment with two movieclips on the stage. They are named YellowBox and RedBox in my library. I have linked the following code to the YellowBox movieclip:
package
    import flash.display.MovieClip;
    import flash.events.MouseEvent;
    public class YellowBox extends MovieClip
        public function YellowBox()
            this.addEventListener(MouseEvent.ROLL_OVER, rollOverHandler);
        public function rollOverHandler(event:MouseEvent):void
            this.x = x + 3;
What I would like to do is call the YellowBox() function on my RedBox MovieClip with the following code:
package
    import flash.display.MovieClip;
    import flash.events.MouseEvent;
    public class RedBox extends MovieClip
        public function RedBox()
            YellowBox();
I get the following message when I compile: 1136: Incorrect number of arguments.  Expected 1.
Any help explaining the process of communicating between classes would be greatly appreciated. This experiement is just an attempt to gain a greater understand of how classes can access and use each other's methods. Thanks!
Also, any tips on inserting code in a more readable fashion as I have seen in other posts ...

Answer 1

Its a concept called Composition, where your class will use Delegation to yellow class to perform a task.
Key Object Oriented Terms when you are ready to know more about class's and their structures
Composition means that a class has another class in its posession, and delegation is when a class tells another to do something.