public void updateUI() {
        
        privatekey.setEnabled(!DaEncrypter.symmetric());
        
        if (input.getText().isEmpty()) {
            output.setText("");
            return;
        }
        
        if (key.getText().isEmpty()) {
            return;
        }
        
        String outputTxt;

        if (decrypt) {
            outputTxt = DaEncrypter.decrypt(input.getText(), (String) cipher.getSelectedItem());
        } else {
            outputTxt = DaEncrypter.encrypt(input.getText(), (String) cipher.getSelectedItem());
        }

        output.setText(outputTxt);
    }