public Object execute(ExecutionEvent event) throws ExecutionException {
// open file dialog
Shell shell = HandlerUtil.getActiveWorkbenchWindowChecked(event).getShell();
final TransformationDialog dialog = new TransformationDialog(shell);
dialog.open();
final String[] files = dialog.getFiles();
if (files != null && files.length > 0) {
Job job = new Job("Generating DataDictionary") {
protected IStatus run(IProgressMonitor monitor) {