ORB client = getClientORB();
Registry registry = getRegistry(principal);
CallbackService service = (CallbackService) registry.lookup("service");
LoggingCallback callback = new LoggingCallback();
Callback callbackProxy = (Callback) client.exportObjectTo(
callback, getServerURI(), user, password);
service.addCallback(callbackProxy);
for (int i = 0; i < count; ++i) {
service.invoke(new Integer(i));