private void btn_Submit_Click(object sender, EventArgs e)
        {
            // code xu ly sua thong tin thuoc
            Medicine mdc = new Medicine();

            mdc.ID_Medicine    = Convert.ToInt32(textBox_MedicineID.Text);
            mdc.Name           = textBox_MedicineName.Text;
            mdc.Uses           = textBox_Uses.Text;
            mdc.Price          = Convert.ToInt32(textBox_Price.Text);
            mdc.TotalInventory = Convert.ToInt32(textBox_Inventory.Text);
            mdc.Note           = textBox_Note.Text;
            mdc.MostUsedMonth  = textBox_MostUsed.Text;

            mdc.MedicineGroup = UcQuanLyThuoc.medicineGroup;
            if (comboBox_MedicineGroup.SelectedIndex != -1)
            {
                mdc.MedicineGroup = comboBox_MedicineGroup.SelectedItem.ToString();
            }

            mdc.Unit = UcQuanLyThuoc.unit;
            if (comboBox_Unit.SelectedIndex != -1)
            {
                mdc.Unit = comboBox_Unit.SelectedItem.ToString();
            }

            ctrl.Update(mdc);

            // thong bao thanh cong
            MessageBox.Show("Sửa thành công", "Thông báo", MessageBoxButtons.OK, MessageBoxIcon.Information);

            // dong form
            Close();
        }