title: How to use AJAX in Dart with async = true
body: <p>I found a <a href="http://groups.google.com/a/dartlang.org/group/misc/browse_thread/thread/e6911c6aabb35587/e72c5047b94cabc3?show_docid=e72c5047b94cabc3#" rel="noreferrer">reference</a> for an <code>XMLHttpRequest</code></p>
  
  <pre><code>  final req = new XMLHttpRequest();
    req.open('GET', '${Sections.home}/data/$name', false);
    req.send();
    _htmlBody = req.responseText; 
  </code></pre>
  
  <p><a href="https://code.google.com/p/dart/source/browse/branches/bleeding_edge/dart/client/samples/swarm/DataSource.dart#224" rel="noreferrer">Full Source</a></p>
  
  <p>But this is for <code>async = false</code>, is there a working example of <code>async = true</code>?</p>