title: Can't set "Content-Type" for URLRequest in as3
body: <p>I'm trying to set Content-Type for URLRequest headers to "application/json".
  Here is the code:</p>
  
  <pre><code>var request:URLRequest = new URLRequest("http://localhost");
  request.contentType =  "application/json; charset=UTF-8";
  </code></pre>
  
  <p>But as you can see on screenshot Content-Type is not in headers:</p>
  
  <p><a href="http://screencast.com/t/vHxHbSUOFM" rel="nofollow">http://screencast.com/t/vHxHbSUOFM</a></p>
  
  <p>But it's in request body:</p>
  
  <p><a href="http://screencast.com/t/irB16taO" rel="nofollow">http://screencast.com/t/irB16taO</a></p>
  
  <p>How to make it right?</p>