// First pass, extract strings only
for (var i = 0; i < len; i++) {
var key = keys[i];
if (typeof(obj[key]) == 'string') {
if (key == '$t') {
xml += obj[key];
} else {
xml = xml.replace(/>$/, '');
for (var i = 0; i < len; i++) {
var key = keys[i];
if (Array.isArray(obj[key])) {
var elems = obj[key];
var l = elems.length;
for (var j = 0; j < l; j++) {
xml += '<' + key + '>';