public LoginWindow(MainWindow mainWindow, Logic logicRef)
 {
     mainWindow_ = mainWindow;
     logicRef_   = logicRef;
     InitializeComponent();
     TB_username.Focus();
     TB_username.SelectAll();
 }
        //Opretter en metode der verificerer logindet
        private void verifyLogin()
        {
            if (logicRef_.checkLogin(TB_username.Text, PWB_password.Password))
            {
                this.Close();
                mainWindow_.Show();
                mainWindow_.SoSecNb = TB_username.Text.ToString();
            }

            else
            {
                MessageBox.Show("Forkert brugernavn eller adgangskode");
                PWB_password.Password = "";
                TB_username.Focus();
                TB_username.SelectAll();
            }
        }