private void button4_Click(object sender, EventArgs e) { if (textBox6.Text.Equals("") || textBox5.Text.Equals("") || textBox2.Text.Equals("") || textBox8.Text.Equals("")) { MessageBox.Show(@"Please do not leave any fields empty"); } else { int number = int.Parse(textBox6.Text); int season = int.Parse(textBox5.Text); string title = textBox2.Text; double rating = double.Parse(textBox8.Text); List <Person> cast = mainCast.Cast <Person>().ToList(); Episode newEpisode = new Episode(number, season, title, cast, rating, show); show.AddEpisode(newEpisode); MessageBox.Show(@"Episode successfully created"); Close(); } }