private void buttonThem_Click(object sender, EventArgs e)
{
var formTruongThem = new FormTruongThem(null);
formTruongThem.FormClosing += new FormClosingEventHandler(ChildFormClosing);
formTruongThem.ShowDialog();
}
private void buttonSua_Click(object sender, EventArgs e)
{
string id = dataGridViewTruong.CurrentRow.Cells[0].Value.ToString();
var formTruongThem = new FormTruongThem(id);
formTruongThem.FormClosing += new FormClosingEventHandler(ChildFormClosing);
formTruongThem.ShowDialog();
}