private void viewCustomerToolStripMenuItem_Click(object sender, EventArgs e)
        {
            fCustomer f = new fCustomer();

            this.Hide();
            f.ShowDialog();
            this.Show();
        }
        private void btnCheckin_Click(object sender, EventArgs e)
        {
            fCustomer f = new fCustomer();

            this.Hide();
            f.ShowDialog();
            this.Show();
        }