title: getting xml post data in a function called with ajax
body: <p>I have </p>
  
  <pre><code>$.ajax({
      type: "POST",
      dataType: "xml", 
      url: getUrl('/GetPeriodicStats/'), 
      data: XML.innerHTML,
      success: function(c)
      {
  </code></pre>
  
  <p>I need to get  XML.innerHTML in GetPeriodicStats.
  I know it's supposed to be in $_POST variable, but what index do I write for it ?
  I tried $_POST['data'], but it's not good...</p>
  
  <p>What should I write in $_POST[???]  ?</p>