FLV playback that won't stop

Have been searching all day for a solution to this, i have read a million times “just put stop();!” but it’s not working…

I need my video to stop when you navigate to the next page, but it’s continuing in the background…

storybutton.addEventListener(MouseEvent.CLICK, StoryButtonClick);
function StoryButtonClick(event:MouseEvent):void {
      myVideo.stop();
      trace("This button is Clicked!");
      gotoAndPlay("page1");
}

That’s my code - as you can see i’m putting it in there, and myVideo is set as the instance name but i keep getting an undefined property error.

I’m probably doing something really silly, but getting very confused by AS3.0 event listeners and haven’t had a good look at it but rushing to meet a deadline! Can anyone please help?