static public void play(String filename) {
		if (filename == null)
			return;
		// stop
		if (musicfile != null && !musicfile.equals(filename))
			stop();
		musicfile = filename;

		int p = musicfile.lastIndexOf(".");
		String ext = musicfile.toLowerCase().substring(p);
		if (ext.equals(".mid") || ext.equals(".midi")) {
			playMidi();
		} else if (ext.equals(".mp3")) {
			playMp3();
		} else {
			playOpenALMusic();
		}
		setStopFlag(false);
	}