private void btXoaLop_Click(object sender, EventArgs e)
{
try
{
int maHS = Convert.ToInt32(tbMaHs.Text);
HocSinhDAL hsDAL = new HocSinhDAL();
hsDAL.XoaHSLop(maHS, idLop);
HienThiDSLop();
}
catch
{
}
}