title: Studio 3 error message re W3C validation
body: <p>Just a quick question from a newbie. Has anyone else using Aptana Studio 3 been getting any error messages when using W3C validation?</p>
  
  <pre><code>Status: 403 Forbidden Vary: Referer Content-type: text/html
  
  Markup Validation Service
  
  Sorry! This document can not be checked.
  No User-Agent header found!
  </code></pre>
  
  <p>A quick Google suggests that other editor/IDE users are experiencing something similar, e.g. HTML-Kit. It looks as if the W3C validation service is expecting a user-agent string as would be provided directly by a browser but presumably isn't by an editor/IDE?</p>
  
  <p>I know that there are ways around the issue by using a different validation service or checking the code via a browser. Just thought I would flag it up.</p>