Hi.
user
Hello, how can I serve you the best today?
assistant
I want to book a ticket from DEN to LAS. Could you book a ticket?
user
Sure, can I know your good name please?
assistant
My name is Daniel Green.
user
 When you are willing to travel?
assistant
Depart date is May, 29 and return by May, 31.
user
Do you need direct flight or connecting flight?
assistant
I would prefer connecting flight.
user
 Would you let us know if you have any other preferences?
assistant
I prefer business class.
user
Sorry to say that, there are no flights available on the routes of your journey.
assistant
Thank you.
user
Thank you for opting us.
assistant