generate response: I'm heading to Stansted Airport, I need to book for 2 people and can I please get a reference number?. Intent: book_train. Slots: train-bookpeople=2, train-day=thursday, train-departure=cambridge, train-destination=stansted airport, train-leaveat=21:00
Response: Sure thing. The reference number is WRAD7NNO . Can I assist with anything else?