You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am Mark Roberts. I am planning to book a ticket from IAD to PHX. Can you please help me out to book a ticket for me?

ASSISTANT: Sure Mark, can I know the travel dates please?

USER: I would like to travel on 01/20 and return back on 01/22.

ASSISTANT: Ok, wait a moment please.

USER: Sure.

ASSISTANT: There is a flight in Delta airline with price 100, can I book it?

USER: Please proceed the booking.

ASSISTANT: Your ticket has been booked with flight number 1016.

USER: Thank you for your service.

ASSISTANT: Thank you for approaching us.