a little upgrade to my stop watch program, this stop watch is now an alarm

StopWatchV2.java

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.DecimalFormat;

import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.Clip;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

/*
 This is my upgraded StopWatch program, this version has an alarm that sounds when the counter reaches 0, I
 have got rid of all of the old comments & I have only commented on here where I have changed things from
 version 1. To make this work you will have to put a wav file
 with the name sound.wav into a folder then add that folder to the projects build path, if you right click  
 your java project in Eclipse then
 go to properties & then click Java Build Path, then click the Libraries tab, then Click the Add Class Folder   
 button.
 go to your project & select the folder you put sound.wav in, then click ok, then refresh(F5).
 if you use netBeens or some other IDE then try googling "java change build path" + your IDE's name
 */
public class StopWatchV2 extends JFrame
{
	//swing components
	private JPanel panel = new JPanel();
	private JTextField text = new JTextField();
	private JLabel label = new JLabel();
	private JLabel whiteLabel = new JLabel();
	private JButton button = new JButton();
	//constants
	static final int WIDTH = 66;
	static final int HEIGHT = 120;
	static final int FPS = 100; 
	static final long OPTIMAL_TIME = 1000000000 / FPS;
	//other
	private boolean running = true;
	private boolean countStart = false;
	private boolean countOver = false;
	private double counter = 0;
	private Font font = new Font("Verdana", 0, 8);
	private DecimalFormat numFormat = new DecimalFormat();

	//new
	public static synchronized void playSound(final String path)
	{
		new Thread(new Runnable()
		{
			public void run()
		    {
				try
		        {
		          Clip clip = AudioSystem.getClip();
		          AudioInputStream inputStream = AudioSystem.getAudioInputStream(StopWatchV2.class.getResourceAsStream(path));
		          clip.open(inputStream);
		          clip.start();
		        } 
		        catch (Exception e) {System.exit(0);}
		      }
		  }).start();
	}
	
	public static void main(String args[]){new StopWatchV2();}
	public StopWatchV2()
	{
		setSize(new Dimension(WIDTH, HEIGHT));
		setDefaultCloseOperation(3);
		getContentPane().add(panel);
		setLocationRelativeTo(null);
		setResizable(false);
		setVisible(true);
		panel.setLayout(null);
			
		makeGui();
		repaint();
			
		long lastLoopTime = System.nanoTime();
		while(running)
		{
	    	long now = System.nanoTime();
	    	long updateLength = now - lastLoopTime;
	    	lastLoopTime = now;
	    	double delta = updateLength / ((double)OPTIMAL_TIME);

	    	update(delta);
	    	paintGui();
	    	    
	    	try{Thread.sleep((lastLoopTime-System.nanoTime())/1000000 + 10 );}
	    	catch(Exception ex){}
			}      
		}
		public String customFormat(String pattern, double value)
		{
			numFormat.applyPattern(pattern);
			return numFormat.format(value);
		}
		private void makeGui() 
		{
			whiteLabel.setBounds(WIDTH/2-2, 0, WIDTH, HEIGHT);
			label.setBounds(WIDTH/2-2, 8, WIDTH, 10);
			text.setBounds(WIDTH/2-2, 33, WIDTH, 21);
			button.setBounds(WIDTH/2-2, 62, WIDTH, 18);
			
			text.setText("0.00");
			label.setText("ALARM       SET");//changed
			button.setText("start");
			
			label.setFont(font);
			
			text.setBackground(Color.gray);
			panel.setBackground(Color.black);
			whiteLabel.setBackground(Color.white);
			whiteLabel.setOpaque(true);
			
			panel.add(label);
			panel.add(text);
			panel.add(button);
			panel.add(whiteLabel);
			
			button.addActionListener(
					new ActionListener()
					{
						public void actionPerformed(ActionEvent event) 
						{
							if(countStart) countStart = false; 
							else 
							{
								countStart = true;
								try
								{
									counter = Integer.parseInt(text.getText());
								}
								catch(NumberFormatException ex) {text.setText("0.00");}
							}
						}
					}
					);
		}
		private void update(double delta)
		{
			if(countStart)
			{
				counter -= delta*.01;
				if(counter <= 0)
				{
						counter = 0;
						countStart = false;
						countOver = true;
				}
				if(countOver) playSound("/sound.wav");//new, plays sound when the counter reaches 0
			}
		}
		private void paintGui()
		{
			if(countStart)
			{
				text.setText(customFormat("0.00", counter));
				text.setEnabled(false);
				button.setText("stop");
			}
			else
			{
				text.setEnabled(true);
				button.setText("start");
				if(countOver) text.setText(customFormat("0.00", counter));
				countOver = false;
			}
		}
}