title: Significance / Usefulness / purpose of new jQuery.ajax way which returns the jqXHR object
body: <p>as of 1.5/1.51 version of jQuery we can make an ajax request like this</p>
  
  <pre><code>var jqxhr = $.ajax({ url: "example.php" })
      .success(function() { alert("success"); })
      .error(function() { alert("error"); })
      .complete(function() { alert("complete"); });
  
  // Set another completion function for the request above
  jqxhr.complete(function(){ alert("second complete"); });
  </code></pre>
  
  <p>1> 
  i am still looking for some example/ demos / some info to know what  significant purpose does this way of doing jQuery.ajax serves that previous way was not serving</p>
  
  <p>2> How much useful is this jqXHR object.</p>
  
  <p>3> Iam looking for some practical usefulness</p>