Hey. I'm looking for a train from stansted airport.
What day will you be traveling?
I plan to go on tuesday.
What is your destination ?
My destination is cambridge. 
There are several.  Do you have a time you need to travel specifically?
The train should arrive by 10:00 if at all possible.
There are trains departing every hour.  TR5077 would get in in at 8:52, does that work for you?
That sounds perfect. Can I get the reference number from the booking?
How many tickets would you like?
I would like 4 tickets. 
Booking was successful, the total fee is 40.4 GBP payable at the station. Reference number is : WWW231NO. Is there anything else you need?