@Override
protected void onUpdate(AjaxRequestTarget target) {
final String oidStr = breadcrumbChoice.getInput();
final EntityModel selectedModel = breadcrumbModel.lookup(oidStr);
if(selectedModel == null) {
final MessageBroker messageBroker = IsisContext.getAuthenticationSession().getMessageBroker();
messageBroker.addWarning("Cannot find object");
String feedbackMsg = JGrowlUtil.asJGrowlCalls(messageBroker);
target.appendJavaScript(feedbackMsg);
breadcrumbModel.remove(oidStr);
return;
}