final String searchText = display.getFilterTextBox().getValue();
boolean caseSensitive = display.getCaseSensitiveChk().getValue();
ReplaceText action =
new ReplaceText(transUnits, searchText, replacement,
caseSensitive);
PreviewReplaceText previewAction = new PreviewReplaceText(action);
dispatcher.execute(previewAction,
new AsyncCallback<PreviewReplaceTextResult>() {
@Override
public void onFailure(Throwable e) {