$(document.body).append("<br/>" + html);
w( $.isXMLDoc( document ) );
w( $.isXMLDoc( document.body ) );
w( $.isXMLDoc( document.getElementById("btn") ) );
var xmlStr = '<?xml version="1.0" encoding="UTF-8"?>';
xmlStr += '<username>CodePlayer</username>';
var xmlDoc = $.parseXML( xmlStr );
w( $.isXMLDoc( xmlDoc ) );