private void btnShowYoungPersons_Click(object sender, EventArgs e) { richTextBoxLog.Text = ""; List <Person> youngPeople = school.GetYoungPersons(Convert.ToInt32(tbxSearchAge.Text)); if (youngPeople.Count != 0) { richTextBoxLog.Text = "Found:\n\n"; foreach (Person person in youngPeople) { richTextBoxLog.Text += person + "\n---------------------\n"; } } }