generate response: am asking for the reference number please. Intent: book_restaurant. Slots: restaurant-area=west, restaurant-bookday=monday, restaurant-bookpeople=5, restaurant-booktime=19:00, restaurant-food=vietnamese, restaurant-name=thanh binh, restaurant-pricerange=cheap
Response: My apologies, it seems that this particular booking is unavailable. Would you like to book a different time or day?