Sound in browser not ending properly

Hi, I have a song that is played when a user click on a button. When they close the window, the song should end, but it doesn't. I even have the songs stop playing in the stop() and destroy() functions, but it isn't working. It only works when it runs in eclipse's applet viewer.

Code Java:

AudioClip song;
.....
	public void actionPerformed(ActionEvent evt) {
 
			if(evt.getSource() == song1)
			{
				song= getAudioClip(getDocumentBase(), "In The End.wav");
				playSong();
			}
			else if(evt.getSource() == song2)
			{
				song = getAudioClip(getDocumentBase(), "What I've Done.wav");
				playSong();
			}
			else if(evt.getSource() == song3)
			{
				song = getAudioClip(getDocumentBase(), "New Divide.wav");
				playSong();
			}
			else if(evt.getSource() == song4)
			{
				song = getAudioClip(getDocumentBase(), "Somewhere I Belong.wav");
				playSong();
			}
 
		}
public void destroy()
	{
		if(isPlaying)
			song.stop();
	}
	public void stop()
	{
		if(isPlaying == true)
			song.stop();
	}