if (fileChooser == null) {
fileChooser = new JFileChooser();
fileChooser.setDialogTitle(MESSAGES.getString("FileChooser.Title"));
// fileChooser.setAcceptAllFileFilterUsed(true);
fileChooser.addChoosableFileFilter(new MultiExtFileFilter("netCDF file", "cdf", "nc"));
fileChooser.addChoosableFileFilter(new MultiExtFileFilter("NeXus file", "nxs"));
fileChooser.addChoosableFileFilter(new MultiExtFileFilter("hdf5 file", "hdf"));
fileChooser.addChoosableFileFilter(new MultiExtFileFilter("data file", "hdf", "nxs",
"cdf", "nc"));
}
int returnVal = fileChooser.showOpenDialog(this);