private void EditTrip_Click(object sender, EventArgs e)
        {
            if (dataGridView1.Rows.Count > 0)
            {
                var chinhsua = dataGridView1.SelectedRows[0].DataBoundItem as Portion;
                var pf       = new EditPortion(chinhsua);

                if (pf.ShowDialog() == DialogResult.OK)
                {
                    portionBindingSource.ResetBindings(false);
                }
            }
            else
            {
                MessageBox.Show("Sorry, There Are Nothing To Edit \n You Can add some portions or Delete Agency ...", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
        private void AddTrip_Click(object sender, EventArgs e)
        {
            var pf = new EditPortion();

            if (pf.ShowDialog() == DialogResult.OK)
            {
                agency.Portions.Add(pf.Portion);
                portionBindingSource.ResetBindings(false);

                if (dataGridView1.Rows.Count > 1)
                {
                    var lastIdx = dataGridView1.Rows.Count - 1;
                    dataGridView1.Rows[lastIdx].Selected          = true;
                    dataGridView1.FirstDisplayedScrollingRowIndex = lastIdx;
                }
            }
        }