private void ThemLop()
{
maLop = LopBLL.AutoMaLop();
Entities.Lop lop = new Entities.Lop(maLop,
cboLoaiLop.SelectedValue.ToString(),
txtTaoLop.Text,
Int32.Parse(txtNam.Text),
cboGVCN.SelectedValue.ToString(),
Int32.Parse(txtSS.Text));
if (!LopBLL.ThemLop(lop))
{
MessageBox.Show("Thêm lớp thất bại");
}
}