Acces the same array in other .as file gives message it don't exist..

Question

I am working on a little shooter as a project for learning as3.
I have struggled a lot with as3 syntax but am willing to bite the bullet and hope someday the light will shine...
the problem:
I have created three movieclips in a fla.
I connected 4 .as files to that fla:
bomber.as
bullet.as
kanon.as
shooter.as (connected to the file/stage itself).
All the behaviors of the mc's are described in packages in their own connected .as file.
I want to do a hitTestObject with all the "bullets" and the "bomber".
inside the as file f the bullet I make an array to store the bullets.
when I want to acces this same array in another .as file i get a message it don't exist..
Someone can suggest a solution...?
any help is very much appreciated!

Answer 1

package {
    import flash.display.MovieClip;
    import flash.events.MouseEvent;
    import flash.events.KeyboardEvent;
    import flash.events.*;//ik mankeer een event; ik weet niet welke, daarom importeer ik maar alle events...
    import flash.utils.Timer;
    import flash.utils.*;
    import kanon_mc;
    public class shooter extends MovieClip {
        public var varkanon:kanon_mc=new kanon_mc;
        public function shooter() {
            mijnTimer.addEventListener(TimerEvent.TIMER,tikTak);
            mijnTimer.start();
            varkanon=new kanon_mc  ;
            stage.addChild(varkanon); 
            varkanon.x=10; 
            varkanon.y=10; 
            //varkanon.x=stage.stageHeight-varkanon.height;
            stage.addEventListener(KeyboardEvent.KEY_DOWN,keyDownHandler);
            stage.addEventListener(KeyboardEvent.KEY_UP,keyUpHandler);
TypeError: Error #1009: .... object  null ...
at kanon_mc()
at shooter()
what am I doing wrong?
the shoother is attached to the document and kanon_mc is a movieclip in the library.