actionscript 3 - How to import a document class file into another flash file?

Question

I have 2 .fla files and one of them is associated with a class file called DocumentMain, it is a game. and what I want is when I click "stat" on the first .fla file it takes me to the game swf file.

I did the myLoad function and it look like this :

btnstart.addEventListener(MouseEvent.CLICK,gamecontent);
function gamecontent(myevent:MouseEvent):void
{
   var myLoader:Loader = new Loader ();
   var myURL:URLRequest = new URLRequest("game.swf");
   myLoader.load(myURL);
   addChild(myLoader);
} 

but I get an Error which is :

TypeError: Error #1009: Cannot access a property or method of a null object reference. at DocumentMain()

Answer 1

instead of addChild(myLoader); add :

myLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, onCompleteHandler);

then create this function:

function onCompleteHandler(loadEvent:Event):void{
    addChild(loadEvent.currentTarget.content);
}

or add this inisde DocumentMain() class:

public function DocumentMain():void{
            addEventListener(Event.ADDED_TO_STAGE, init);
        }
        private function init(e:Event):void{...