学步园

                                                       
2 如果用Post方法需要加下面中间的那句话，否则参数传不过去
                          

xmlHttpRequest.open("POST","login.jsp",true);
xmlHttpRequest.setRequestHeader("Content-Type","application/x-www-form-urlencoded;charset=UTF-8");

xmlHttpRequest.send("user="+username+"&pwd="+password);