public void actionPerformed(ActionEvent e) {
		if (automaton.getInitialState() == null) {
			JOptionPane.showMessageDialog(environment,
					"The automaton needs an initial state.",
					"No Initial State", JOptionPane.ERROR_MESSAGE);
			return;
		}

		AutomatonChecker ac = new AutomatonChecker();
		if (!ac.isNFA(automaton)) {
			JOptionPane.showMessageDialog(environment, "This is not an NFA!",
					"Not an NFA", JOptionPane.ERROR_MESSAGE);
			return;
		}

		ConversionPane convert = new ConversionPane(
				(FiniteStateAutomaton) automaton.clone(), environment);
		environment.add(convert, "NFA to DFA", new CriticalTag() {
		});
		environment.setActive(convert);
	}