You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you today?

USER: William Mitchell here. Can you please help me in booking a flight ticket from LAS to SFO?

ASSISTANT: Sure, may I know your journey dates that you have planned to travel?

USER: Sure, my planned travel dates are from May 19 to May 21.

ASSISTANT: Do you have any connection limit?

USER: Yes, I need a connecting flight.

ASSISTANT: In which class do you want to travel?

USER: I am flexible with any class.

ASSISTANT: Can I know your preferable timings to travel?

USER: I would like to depart in the evening.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: We found a connecting flight in United Airlines with flight number 1019 having an economy class departs in the evening at 22:00 PM. Shall I proceed with booking?

USER: Ok, please proceed.

ASSISTANT: Your booking has been done.

USER: Thank you for your service.

ASSISTANT: Thank you for opting us.