title: how to prevent rotation of subview to portrayed mode
body: <p>I am trying to add a sub view to the main view when a button is tapped.</p>
  
  <ul>
  <li><p>The main view supports both landscape modes and portrait mode.</p></li>
  <li><p>The sub view supports only landscape mode.</p></li>
  </ul>
  
  <p>How do I go about doing this?</p>