coding

private void setupListenersForValidation() {
		this.phoneNumberTextField.textProperty().addListener((observable, oldValue, newValue) -> {
				if (newValue != null) {
					if (!newValue.matches("\\(\\d{3}\\)\\d{3}-?\\d{4}")) {
						ContactGuiCodeBehind.this.phoneNumberTextField.setText(oldValue);
						ContactGuiCodeBehind.this.idErrorLabel.setVisible(true);
					} else {
						ContactGuiCodeBehind.this.idErrorLabel.setVisible(false);
					}
				}
		});
	}