function SaveUserState() {            if (xmlHttpRequest.readyState == 4 && xmlHttpRequest.status == 200) {                var msg = xmlHttpRequest.responseText;                if (msg == "true") {                    alert("用户状态设置成功!");                }                else {                    alert("用户状态设置失败!");                }            }        }
下面是调试的信息,显示不正常,怎么回事呢?
onreadystatechange : {???},
readyState : 4,
responseBody : undefined,
responseStream : {...},
responseText : "",
responseXML : {...},
status : 12030,
statusText : "Unknown"