public HoaDon()
{
InitializeComponent();
this.hdbll = new HoaDonBLL();
string s = hdbll.ThoiGian();
DateTime dt = Convert.ToDateTime(s);
thang1 = Convert.ToInt32(dt.Month.ToString()) + 1;
thang.Text = thang1.ToString() + "/" + dt.Year.ToString();
dgvTenDV.DataSource = hdbll.DV();
butSua.Enabled = false;
butThem.Enabled = false;
butXoaDV.Enabled = false;
butLapHD.Enabled = false;
butXoaHD.Enabled = false;
button1.Enabled = false;
}
