final MyDialog popup = new MyDialog(null);
popup.addTextArea(null).setSize("600", "150");
popup.getTextArea().setText("please wait ...");
PortalControl.getInstance().notifyActivity(true);
popup.setText("Unregistering ontology ...");
popup.center();
popup.show();
AsyncCallback<UnregisterOntologyResult> callback = new AsyncCallback<UnregisterOntologyResult>() {
public void onFailure(Throwable thr) {
PortalControl.getInstance().notifyActivity(false);