public JCount() {
		setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
		countField = new JTextField("100000000");
		add(countField);
		currentCount = new JLabel("0");
		add(currentCount);
		JButton startButton = new JButton("start");
		worker = null;

		startButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				int initialCount = 100000000;
				if (worker != null) worker.interrupt();
			
				initialCount = Integer.parseInt(countField.getText());

				worker = new countWorker(initialCount);
				worker.start();
			}
		}); 
		add(startButton);
		JButton stopButton = new JButton("stop");
		stopButton.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				if (worker != null) worker.interrupt();
			}
		});
		add(stopButton);
		add(Box.createRigidArea(new Dimension(0,40)));
	}