generate response: Does the train depart on Friday? Does it go to Stevenage?. Intent: book_train. Slots: train-bookpeople=7, train-day=thursday, train-departure=cambridge, train-destination=stevenage, train-leaveat=14:30
Response: I'm sorry, earlier you said you were going to Ely, but now you're asking about stevenage. What is your destination, please?