<!DOCTYPE html>
<html>
<body>

<p id="demo"></p>

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

function myFunction(xml) {
    var x, txt, xmlDoc;
    xmlDoc = xml.responseXML;
    x = xmlDoc.getElementsByTagName("title")[0].childNodes[0];
    txt = x.nodeValue + "<br>";
    x.insertData(0,"Easy ");
    txt += x.nodeValue;
    document.getElementById("demo").innerHTML = txt;
}
</script>

</body>
</html>