private void btnOk_Click(object sender, EventArgs e)
{
DanhSachGVBUL cls = new DanhSachGVBUL();
PhanCongGiangDay x = new PhanCongGiangDay();
x.MaLop = cboTenLop.SelectedValue.ToString();
dgvDSGV.DataSource = cls.HienThiDS(x);
dgvDSGV.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill;
}
