ajax异步调用取值出现缺少对象

各位大侠，帮帮忙
ajax为
JScript code:

var req;
function testAjax()
{
if (window.XMLHttpRequest) {
alert("0");
req = new XMLHttpRequest();
}else if (window.ActiveXObject) {
alert("1");
req = new ActiveXObject("Microsoft.XMLHTTP");
}
if(req){
req.open("GET", "./jldInfor.do?jl=test&name=ssd", true);
req.onreadystatechange = callback;
req.send(null);
}
}
function callback() {
if (req.readyState == 4) {
if (req.status == 200) {
parseMessage();
}else{
alert ("Not able to retrieve description" + req.statusText);
}
}
}
function parseMessage() {
document.getElementById("sh").value = req.responseXML.getElementsByTagName("name")[0].firstChild.data;
}



action代码为：
Java code:

public ActionForward test(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response) throws Exception{
JldInforFor