求大神指点，登录验证问题

$.ajax({
url:'login.do',
type:'post',
dataType:'json',
data:{userName:$('#username').val(),pwd:$('#pwd').val()},
success:function(data){
alert('00');
if(data.result=='success'){
alert('success');
window.location.href="./index.html";
}
else if(data.result=='notExist'){
alert('用户名错误！');
}else{
alert('密码错误！');
}
},
error:function(data){
alert('服务器繁忙，稍后重试！');
}
});

//后台
@RequestMapping("/login.do")

public @ResponseBody Map<String, Object> login(@ModelAttribute("user")User user
,HttpServletRequest req){
System.out.println(user.getUserName()+":"+user.getPwd());
boolean b=false;
Map<String,Object> data = new HashMap<String,Object>();
try {
b = userservice.checkUser(MD5.GetMD5Code(user.getUserName()),
MD5.GetMD5Code(user.getPwd()));
} catch (UserNameNotExistException e) {
data.put("result","notExist");
System.out.println(e.getMessage());
return data;
}
if(b) {//登录成功，设置session属性
System.out.println("controller");
HttpSession s =req.getSession();
s.setMaxInactiveInterval(30);
s.setAttribute("username", "Exist");
data.put("result", "success");
return data;
}
else {
data.put("result","error");
return data;
}
}
问题：ie浏览器开了调试，能正常运行，关闭调试，就没反应了，360浏览器直接走了error：function 为什么，求大神指教！！