title: selector elements from iframe in parent
body: <p>I find that it's very hard to select elements in an iframe and make some action in my parent page. Here is my codes and it does not work.</p>
  
  <p>In my parent codes:</p>
  
  <pre><code>//(JS PART)
  var $currentIFrame = $('#screen'); 
     alert($currentIFrame.contents().find("#abc").type);
  
  //(body part)
    &lt;iframe id="screen" name="screen" width="100%" height="100%" src="test.php"&gt;
  
                     &lt;/iframe&gt;
  </code></pre>
  
  <p>in my iframe files:</p>
  
  <pre><code>//(body part)
  &lt;input type="text" id="abc" name="abc"&gt;
  </code></pre>
  
  <p>While, the result is "undefined" instead of "text".</p>