Save xml using Javascript

if (window.XMLHttpRequest) {
           xhttp = new XMLHttpRequest();
       }
       else // code for IE5 and IE6
       {
           xhttp = new ActiveXObject("Microsoft.XMLHTTP");
       }

       xhttp.open("GET", "books.xml",false);
       xhttp.setRequestHeader("Accept", "text/xml");
       xhttp.send();
       xmlDoc = xhttp.responseXML;
       x = xmlDoc.getElementsByTagName("title")[0].childNodes[0];

       x.nodeValue = "Easy Cooking";
       xmlDoc.Save("books.xml");