如何解析回调中的XML文档?

我分析它只是为了归还尸体? 下面是我的代码片段:

goog.net.XhrIo.send("/blogs/create?authenticity_token="+
       goog.string.urlEncode(authtoken), function(e) {
           var xhr = /** @type {goog.net.XhrIo} */ (e.target);
           var responseXml = xhr.getResponseXml();

           var parent = goog.dom.getElement('response');
           goog.dom.setTextContent(parent, responseXml.body); /** This returns 
                                              undefined rather than the body itself! */

           }, 'POST', "&body="+goog.string.urlEncode(someHTMLContent), {
              'Accept' : 'text/xml'
});