XML DOM createElementNS() Methode

var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
   if (this.readyState == 4 && this.status == 200) {
       myFunction(this);
   }
};
xhttp.open("GET", "books.xml", true);
xhttp.send();

function myFunction(xml) {
    var x, y, z, i, newel, newtext, xmlDoc, txt;
    xmlDoc = xml.responseXML;
    txt = "";
    x = xmlDoc.getElementsByTagName("book");
    // Create element nodes with namespace and text nodes
    for (i = 0; i < x.length; i++) {
        newel = xmlDoc.createElementNS("p", "edition");
        newtext = xmlDoc.createTextNode("First");
        newel.appendChild(newtext);
        x[i].appendChild(newel);
    }
    // Output all titles and editions
    y = xmlDoc.getElementsByTagName("title");
    z = xmlDoc.getElementsByTagNameNS("p","edition");
    for (i = 0; i < y.length; i++) {
        txt += y[i].childNodes[0].nodeValue +
        " - " +
        z[i].childNodes[0].nodeValue +
        " edition." +
        " Namespace: " +
        z[i].namespaceURI + "<br>";
    }
    document.getElementById("demo").innerHTML = txt;
}

createElementNS(ns,name)