Cannot access a property or method of a null object reference error

programming flash
1

I have a my project that has three frames on the main timeline.
Frame Label MovieClip Instance Name Class file
Intro_Frame -> Intro_symbol -> Intro_Page
Content_Page -> Content_symbol -> Content
Credits_Page -> Credits_symbol -> Credits

My plan : I have buttons on the bottom of each page. One on the intro page, two on the Content page (to go back to intro and to go to the credits page) and one on my Credits page to go back to the content.

My Intro page has everything physically on the stage, and my other two pages have everything dynamically instantiated. For some reason all of the objects when I put a trace(MovieClip(this.parent)) it always prints out null but for the objects in my intro page that are physically put on the stage, it prints out the parent just fine.

I have a transition from my intro page to my content page in actual tweens on the timeline and have given it a label. But for some reason I can’t access it because none of my dynamic things have parent names.

Graphically it’s as follows:

I’m at button on credits -> go to parent Credits -> go to parents Card (class / container movieclip that holds everything) -> back down to Intro_symbol -> gotoAndPlay(“Transition2”);

It always returns an error saying “cannot access a property or method of a null object reference”

Any ideas?

I’ve uploaded the code for you to take a look at.

Right now I have it so that on the beginning frame, the card class (the container) adds the Intro_symbol as a child. It works fine, then when you click the button it moves it to the transition frame on the timeline in the Intro_symbol. It plays fine till it moves the the frame at the end labeled “gotocontent”.

I have an addEventListener(Event.ENTER_FRAME, enterFrameHandler) then if(currentFrame == “gotocontent”) it moves the main timeline in the Card object to “Content_Page”.

It gets to that page but when I have the same setup in the card class involving action listeners to the if(currentFrame == “Content_Page”) and then it creates the content symbol Content_symbol = new Content() it throws the “Cannot access a propery or method of a null object reference”.

Intro_Page class

package classes
{
    import flash.display.*;
    import flash.events.*;
    import flash.utils.Timer;
    
    public class Intro_Page extends MovieClip
    {
        var peopleDelay;
        public function Intro_Page()
        {
            peopleDelay = new Timer(800);
            peopleDelay.addEventListener("timer", timerHandler);
            this.addEventListener(Event.ENTER_FRAME,enterFrame_handler);
        }
        public function enterFrame_handler(e:Event):void
        {
            if(currentLabel == "Intro")
            {
                people.stop();
                peopleDelay.start();
            }
            else if(currentFrameLabel == "GoToContent")
            {
                trace("goto content if statement in Intro_Page");
                //this.stop();
                this.removeEventListener(Event.ENTER_FRAME,enterFrame_handler);
                Card(this.parent).gotoAndStop("Content_Page");
            }
        }
        
        function timerHandler(e:Event):void
        {
            peopleDelay.reset();
            people.gotoAndPlay("walking");
        }
    }
}

Card class

package classes
{
    import flash.display.*;
    import flash.events.*;
    import fl.transitions.Tween;
    import fl.transitions.easing.*;
    import fl.transitions.TweenEvent;
    import flash.utils.Timer;
    
    public class Card extends MovieClip
    {        
        public var Intro_symbol:Intro_Page;
        public var Content_symbol:Content;
        public var Credits_symbol:Credits;
        public var introBoolean=true;
        public var contentBoolean=true;
        
        public function Card()
        {
            
            this.addEventListener(Event.ENTER_FRAME,enterFrameHandler);
        }
        public function enterFrameHandler(e:Event)
        {
            //Content_symbol = new Content();
            //Credits_symbol = new Credits();
            if(currentFrameLabel == "Intro_Frame" && introBoolean == true)
            {
                introBoolean = false;
                trace("Adding intro to stage");
                Intro_symbol = new Intro_Page();
                this.addChild(Intro_symbol);
                trace("from card to intro: " + this.Intro_symbol);
                Intro_symbol.x=399.1;
                Intro_symbol.y=300.6;
            }
            if(currentFrameLabel == "Content_Page" && contentBoolean == true)
            {
                contentBoolean = false;
                trace("Adding content to stage");
                Content_symbol = new Content(); //THIS LINE RIGHT HERE IF IT IS ALLOWED TO RUN THROWS THE ERROR
                //this.addChild(Content_symbol);
                //Content_symbol.x=0;
                //Content_symbol.y=0;
            }            
        }
    }
}

Here’s all my files. I would have uploaded them here but the zip file is 200k to big.
http://www.megaupload.com/?d=PWC17XI5