Task-oriented dialogue about: train

I'm looking for a train please going to cambridge.
I'd be happy to help with your request, to narrow it down where is your departure site and what time do you want to arrive?
I'm looking for a train leaving from london liverpool street after 20:00 on Friday.
How about train TR8373 that leaves at 21:39?
its ok. book for 8 people and help me get the reference number please
All right, that's done. Your reference number is 3S77WUWE . How else may I help you?
That was everything, thanks!
Have a nice trip thank you.