ArgumentError: Error #2025: The supplied DisplayObject must be a child of the caller.

Question

Evenin' all.
I'm creating a Flash application split up into scenes. One of the scenes is divided into sections of ten frames with keyframes at 1 (home, 10, 20, 30, 40, 50, 60, 70, 80 and 90. Frame #1 is the menu and contains the buttons to skip to each section using the gotoAndStop(); command.
However, I want to be able to skip to #1 from any point using Next/Previous buttons. I have declared the buttons in frame 1 of scene 1 as follows:
I have declared the buttons in frame 1 of scene 1 as follows:
Code:
var nextButton:Button = new Button();
var prevButton:Button = new Button();
var homeButton:Button = new Button();
At each point, I use addChild(nextButton) to add the buttons to  the stage, and when the buttons are clicked it removes them as follows:
Code:
nextButton.addEventListener(MouseEvent.CLICK, goNext);
function goNext(e:Event):void
      removeChild(videoPlayer);
      removeChild(prevButton);
      removeChild(nextButton);
      removeChild(homeButton);
      gotoAndStop(20);
Now, all the 'Next' buttons work but none of the 'Previous'  buttons work, when all they do is gotoAndStop() ten frames backwards  rather than ten frames forwards, I keep getting this error message:
Code:
ArgumentError: Error #2025: The supplied DisplayObject must be a child of the caller.
     at flash.display::DisplayObjectContainer/removeChild()
     at Prototype_fla::MainTimeline/goBack()
The same is happening with the Home buttons, which skip from whichever frame the user is on to the menu. The Next buttons are the only ones working consistently.
Please help, this is really stressing me out, I'm on Flash CS4.
Cheers

Answer 1

You can`t remove the target of your event while it is "active"
you wrote....
nextButton.addEventListener(MouseEvent.CLICK, goNext);
function goNext(e:Event):void
      removeChild(videoPlayer);
      removeChild(prevButton);
      removeChild(nextButton);
      removeChild(homeButton);
      gotoAndStop(20);
instead you should write sth. like:
nextButton.addEventListener(MouseEvent.CLICK, goNext);
function goNext(e:Event):void
  // to be sure that there`s actualloy sth. to remove
      if(videoPlayer!=null){
      removeChild(videoPlayer);
     //similar  
     removeChild(prevButton);
      removeChild(homeButton);                
      e.currentTarget.removeEventListener(MouseEvent.CLICK, goNext)     
      removeChild(e.currentTarget);     
      gotoAndStop(20);
this is probably similar in your other function, too