public void actionPerformed(ActionEvent evt) {
      Object source = evt.getSource();
      if (source instanceof JRadioButton) updateEnabled();
      if (source == ok) ok();
      else if (source == cancel) cancel();
      else if (source == combo) updateList();
      else if (source == fileButton) {
        String directory;
        if (fileIcon == null) directory = null;
        else directory = MiscUtilities.getParentOfPath(fileIcon);
        String paths[] =
            GUIUtilities.showVFSFileDialog(null, directory, VFSBrowser.OPEN_DIALOG, false);
        if (paths == null) return;

        fileIcon = "file:" + paths[0];

        try {
          fileButton.setIcon(new ImageIcon(new URL(fileIcon)));
        } catch (MalformedURLException mf) {
          Log.log(Log.ERROR, this, mf);
        }
        fileButton.setText(MiscUtilities.getFileName(fileIcon));
      }
    }