title: window.opener doesn't work in firefox and chrome but in IE
body: <p>I have a problem with the window.opener function (JS):</p>
  
  <p>I created 3 simple pages to simulate my problem:</p>
  
  <p>test.php:</p>
  
  <pre><code>&lt;html&gt;
      &lt;head&gt;
      &lt;/head&gt;
      &lt;body&gt;
          &lt;input type="button" onclick="window.open('first_page_in_popup.php', 'Popup', 'width=470,height=500');"&gt;    
          &lt;input type="text" id="content" name="content" &gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>first_page_in_popup.php:</p>
  
  <pre><code>&lt;html&gt;
      &lt;head&gt;
          &lt;script type="text/javascript" &gt;
              window.opener.document.getElementById('content').value= "Test from first page in popup";
              window.open('second_page_in_popup.php', 'Popup');
          &lt;/script&gt;
      &lt;/head&gt;
      &lt;body&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>second_page_in_popup.php:</p>
  
  <pre><code>&lt;html&gt;
      &lt;head&gt;
          &lt;script type="text/javascript" &gt;
              window.opener.document.getElementById('content').value= "Test from second page in popup";
          &lt;/script&gt;
      &lt;/head&gt;
      &lt;body&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>Result:
  In IE, the input field has the content "Test from second page in popup".
  In Chrome and Firefox, the content is : "Test from first page in popup".</p>
  
  <p>The Error Message:</p>
  
  <pre><code>window.opener.document.getElementById(...) is null
  </code></pre>