public void LayTrinhDoSoCauVaThoiGian(String lanthi)
{
SqlDataReader dr = SinhVien.LayThongTinThi(mamonhoc, mL, lanthi);
if (dr != null)
{
socau = (dr.GetInt16(0)).ToString();
trinhdo = dr.GetString(1);
thoigianthi = dr.GetInt16(2);
}
dr.Close();
}