title: Accessing parent window elements from iframe
body: <ul>
  <li>I have a <code>customer.jsp</code> page with an <code>iframe</code>.</li>
  <li><code>iframe</code> has a button. on click of the button, i need to access a dialog box which is inside <code>customer.jsp</code> page.</li>
  <li>I tried <code>window.parent.document.getElementById('formDialog');</code> but am getting <code>null</code> value.</li>
  </ul>