title: jQuery $.ajax() function's error message source
body: <p>In the case of failure, the code goes something like:</p>
  
  <pre><code>error: function(msg)
  </code></pre>
  
  <p>where does the <code>msg</code> come from?</p>
  
  <p>EDIT:</p>
  
  <p>I am using this function ($ajax) to call a WEB SERVICE. So if whoever voted this down could explain to me where msg comes from that would be great! Do I set it in web service? If so, how? Please don't copy and paste the definitions.</p>