public void SignIn(string login, string password) { if ((login != null) || (password != null)) { if ((!"".Equals(login)) || (!"".Equals(password))) { if ((!"Username".Equals(login)) && (!"11111111".Equals(password))) { User user = new User(login, password); User userInfo = userService.SignIn(user); if (userInfo == null) { _loginView.ShowMessage("No such user"); return; } _loginView.Confirm(userInfo.Username); return; } } _loginView.ShowMessage("login or password not entered"); return; } _loginView.ShowMessage("Incorrect login or password"); }