http://www.w3.org/TR/XMLHttpRequest/
// Sample about XMLHttpRequest
jQuery.ajax(...,success: function(data, textStatus, XMLHttpRequest)...
XMLDocument
http://www.w3schools.com/Xml/xml_parser.asp
Convert iframe content to XMLDocument
// for IE
var xDoc = iframe1.contentWindow.document.XMLDocument;// for Firefox
var parser = new DOMParser();
var xmlString = (new XMLSerializer()).serializeToString(iframe1.contentDocument.documentElement);
var xDoc = parser.parseFromString(xmlString, "text/xml");
