[Help] Error using EJB

[vuonhongchoem]

I have a Spring Controller and 2 Session bean.
When I declare 2 bean (as follow code), I can use them normally

@Controller
@RequestMapping("index.htm")
public class LoginController
{

    @EJB
    private LoginService loginService;
    @EJB
    private UsersFacade usersFacade;

But when I use UsersFacede in LoginService, userEntityFacade's null.
where I have to configure to use UsersFacade?

@Stateless
public class LoginService
{
    @EJB
    private UsersFacade userEntityFacade;

    public String authentication()
    {
        return "ee:" + userEntityFacade;
    }
}

Sorry, I do not know much English and my poor knowledge.
I'm trying.
Thanks a lot.