private void button2_Click(object sender, RoutedEventArgs e) { Plan p = new Plan(); p = Parser.ParseXML(textBox1.Text); Plan p2 = p.ConsistentAccordance(); //if plan has a consistent accordance, if (p2.HasOfferings()) { MessageBox.Show("The plan has consistent accordance(s):\n" + p2.ToString()); } else { MessageBox.Show("The plan has no consistent accordances."); } }