private void button3_Click(object sender, EventArgs e)
 {
     if (this._item_id > 0)
     {
         frm_serial_numbers _serial = new frm_serial_numbers(this, this._item_id);
         _serial.ShowDialog();
     }
     else
     {
         MessageBox.Show("Select An Item First");
     }
 }
        private void button5_Click(object sender, EventArgs e)
        {
            switch (this._item_id > 0)
            {
            case true:
                frm_serial_numbers _serial = new frm_serial_numbers(this, _item_id);
                _serial.ShowDialog();
                break;

            default:
                MessageBox.Show("You Must Select an Item First");
                break;
            }
        }