generate response: Oh sorry, I wanted a train on Friday, not Saturday. Anything after 08:45 from london liverpool street. to cambridge.. Intent: find_train. Slots: train-day=friday, train-departure=london liverpool street, train-destination=cambridge, train-leaveat=08:45
Response: I'm sorry. There is no train leaving from london live to cambridge on friday by 8:45. Would you like to try a different day or time?