private void btn_add_Click(object sender, EventArgs e)
{
DetailSV f = new DetailSV();
f.delegateType(-1, 0);
f.Show();
cbbLopSH.Text = "All";
show();
}
private void btn_edit_Click(object sender, EventArgs e)
{
DataGridViewRow dr = dataGridViewDSSV.SelectedRows[0];
// get mssv of sv
int mssv = Convert.ToInt32(dr.Cells["MSSV"].Value);
// get class id of sv
int id_class = Convert.ToInt32(dr.Cells["ClassID"].Value);
DetailSV f = new DetailSV();
f.delegateType(mssv, id_class);
f.Show();
show();
}