title: jQuery check if call is cross-domain
body: <p>Am wondering if there is any method to check if the call is a cross-domain call. Maybe something like a flag which tests if it is cross-domain so then I can use another approach.</p>
  
  <p>For example:</p>
  
  <pre><code>$.ajax({
    type: "POST",
    url: "cross-domaincallURL", 
    success: function(response, status, xhr){ 
      if OPTIONS then cross-domain
      if not then not cross-domain 
    }
  });
  </code></pre>