public ActionResult Login_user(Employee_model user)
        {
            if (ModelState.IsValid)
            {
                EmployeeRepository employee_repo = new EmployeeRepository();
                Employee           user_from_db  = new Employee();
                try
                {
                    user_from_db = employee_repo.Get_by_login(user.Login);

                    if (user_from_db != null)
                    {
                        if (user_from_db.password == user.Password.ToString())
                        {
                            if (user_from_db.guid == null) // If the given user logs in for the first time and does not have his guid, he adds guid in db
                            {
                                employee_repo.Add_guid(user_from_db.id);
                            }

                            Session["user_session"] = user_from_db;
                            Session.Timeout         = 1;

                            if (user.Remember_me == true)
                            {
                                HttpCookie ciasteczko = new HttpCookie("user_cookie", user_from_db.guid);
                                ciasteczko.Expires = DateTime.Today.AddDays(1);
                                Response.Cookies.Add(ciasteczko);
                            }

                            return(RedirectToAction("Index", "Visit"));
                        }
                        else
                        {
                            user.Password_valid_message = Resources.Global.Password_incorrect;
                        }
                    }
                    else
                    {
                        user.Name_valid_message = Resources.Global.Login_incorrect;
                    }
                }
                catch (Exception ex)
                {
                    NLog_logger.Loger.Error(ex);
                }
            }

            return(View("Login", user));
        }