private void OKLabel_Click(object sender, EventArgs e) { if (CardNumberTextBox.Text.Length == 16 && DateMonthComboBox.Text.Length > 0 && DateYearComboBox.Text.Length >= 4 && CVVTextBox.Text.Length == 3) { Card c = new Card(); c.setNumber(CardNumberTextBox.Text); c.setDate(DateMonthComboBox.Text, DateYearComboBox.Text); c.setCVV(CVVTextBox.Text); this.DialogResult = DialogResult.OK; } else { label5.Show(); } }