private void comboBoxMaCTT_SelectedValueChanged(object sender, EventArgs e)
{
List <string> myList = bll.GetThongTinCTT(comboBoxMaCTT.SelectedValue.ToString());
textBoxMaTS.Text = myList[0];
textBoxTenTS.Text = myList[1];
dateTimePickerGhiTang.Value = DateTime.Parse(myList[2]);
numericUpDownSoLuong.Minimum = bll.GetMaxSoLuongCTT(comboBoxMaCTT.SelectedValue.ToString()) - bll.GetMaxSoLuong(textBoxMaTS.Text);
numericUpDownSoLuong.Value = int.Parse(myList[3]);
textBoxThanhTien.Text = myList[4];
textBoxNoiDung.Text = myList[5];
SoLuongCu = int.Parse(myList[3]);
//textBoxDonGia.Text = ( ( 10 * int.Parse(myList[4] ) ) / ( 11 * int.Parse(myList[3]) ) ).ToString();
}