public void mouseClicked(MouseEvent e)
  {
    currentPixelPosition = e.getX();
    
    if(currentPixelPosition==0)
    {
      playBeforeButton.setEnabled(false);
      playAfterButton.setEnabled(true);
    }
    else if(currentPixelPosition < sampleWidth)
    {
      playBeforeButton.setEnabled(true);
      playAfterButton.setEnabled(true);
    }
    else if(currentPixelPosition == sampleWidth)
    {
      playBeforeButton.setEnabled(true);
      playAfterButton.setEnabled(false);
    }
    
    if(DEBUG)
      System.out.println("mouse click:  " + currentPixelPosition);
    
    updateIndexValues();
    soundPanel.repaint();
  }