title: XML accessible from URL line but not from script
body: <p>When I type a certain URL in FF, I get the XML returned displayed on the screen, so the web service is apparently working. However, when I try to access it from a local HTML document running JS, I get unexpected behavior. The returned code is "200 OK" <strong>but</strong> there's no text (or rather it's an empty string) nor xml (it's <code>null</code>) in the response sections according to FireBug.</p>
  
  <p>This is how I make the call.</p>
  
  <pre><code>var httpObject = new XMLHttpRequest();
  httpObject.open("GET", targetUrl, true);
  httpObject.onreadystatechange = function () {
    if (httpObject.readyState == 4) {
      var responseText = httpObject.responseText;
      var responseXml  = httpObject.responseXML;
    }
  }
  httpObject.send(null);
  </code></pre>
  
  <p>Why does it happen and how do I tackle it?</p>