title: addEventListener and gotoAndStop for a menu in a game gives error
body: <p>I'm new at flash as3. Today, I am trying to code a menu in a game which will refer to a startscreen for a game to show the buttons for the game. </p>
  
  <p>In this startscreen, there is a button to link back to the menu. It doesn't work. I am getting this, </p>
  
  <p>Error:</p>
  
  <pre><code>TypeError: Error #1009: Cannot access a property or method of a null object reference.
      at SuperSpill_fla::MainTimeline/frame1()
  </code></pre>