title: How do I make php page return a 503 error (or anything non-200)
body: <p>A former developer wrote or client-server api in PHP.  It simply sends messages as xml using post/response in a very simplistic fashion.  The problem is that even when there is an error (ex: invalid arguments passed into the server side) we get a HTTP 200 response with a page like this </p>
  
  <pre><code>&lt;h4&gt;Unknown error!&lt;/h4&gt;
  </code></pre>
  
  <p>In firebug I can see that the actually HTTP response is a 200.  How can we send a different response (ie:503) when we programatically detect in our php code that it is appropriate to do so.</p>