title: How to link the top right 'X' button to close the window with easygui?
body: <p>I am currently working on a small application built with easygui consist with many boxes, on the main Window it has a 'Quit' button with will prompt a <code>ccbox</code> and ask if user decide to close the app or not. I wanted to link the 'X' button (throughout the application) to that box but seems the documentation didn't provide a clear instruction about what variables to put in <code>cancel_choice</code>. Can anyone enlighten me?</p>
  
  <p>The Code I am using:</p>
  
  <pre><code>Choice = buttonbox(MainWinmsg, MainWintitle, MainWinchoice, cancel_choice=MainWinchoice[2])
  </code></pre>
  
  <p>right now the <code>cancel_choice</code> does not work as I am expected to be.</p>
  
  <p>Easygui version is <code>0.98.1</code></p>