private void AccountManager_FormClosed(object sender, FormClosedEventArgs e)
 {
     if (Config.Username != "") // dang nhap thanh cong
     {
         SpendUI spendUI = new SpendUI();
         showControl(spendUI);
     }
     else
     {
         Application.Exit();
     }
 }
        public MainProgram()
        {
            InitializeComponent();

            if (Config.Username == "")
            {
                Account accountManager = new Account();
                accountManager.FormClosed += AccountManager_FormClosed;
                accountManager.ShowDialog();
            }
            else
            {
                SpendUI spendUI = new SpendUI();
                showControl(spendUI);
            }
        }
        private void btnSpend_Click(object sender, EventArgs e)
        {
            SpendUI spendUI = new SpendUI();

            showControl(spendUI);
        }