protected void signIn(String userName, String password) {
		if (productSvc == null) {
			productSvc = GWT.create(ProductService.class);
		}

		AsyncCallback<Boolean> callback = new AsyncCallback<Boolean>() {
			public void onFailure(Throwable caught) {
			}

			public void onSuccess(Boolean valid) {
				if(valid)
					changeToSignedInUI();
			}
		};
		productSvc.verifyAccount(userName, password, callback);
	}