Convert XML to String and append to page

You haven’t told us how you go about displaying that object. XMLSerializer works on DOM nodes, so your object has to be added somewhere, for example:

document.getElementById('SomeDiv').appendChild(xml); 

and if you just want the full xml string to be displayed:

var xmlText = new XMLSerializer().serializeToString(xml);
var xmlTextNode = document.createTextNode(xmlText);
var parentDiv = document.getElementById('SomeDiv');
parentDiv.appendChild(xmlTextNode);