private void button1_Click(object sender, EventArgs e)
        {
            fThemBenhNhan addBenhNhan = new fThemBenhNhan();

            addBenhNhan.ShowDialog();
            // panel2.Controls.Add(addBenhNhan);
            //panel2.Controls.Remove(addBenhNhan);
            //addBenhNhan.Hide();
            //this.Controls.Add(addBenhNhan);
        }
        private void button1_Click_1(object sender, EventArgs e)
        {
            fThemBenhNhan f = new fThemBenhNhan();

            f.ShowDialog();
        }