You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you please guide me in booking my flight ticket from SFO to IAD?

ASSISTANT: Can you please let me know your preferable travel dates for booking flight ticket?

USER: My trip dates will be Mar 27th to May 29th.

ASSISTANT: Do you like to go with a economy class or business class?

USER: I am ok with any class.

ASSISTANT: May I know your other specifications?

USER: I need a flight which should depart in the afternoon.

ASSISTANT: Could you please provide your name for reservation purpose?

USER: I am Gregory Evans.

ASSISTANT: There is a flight-1020 in economy class, shall I confirm it?

USER: You can proceed.

ASSISTANT: Ok, booking is done on UA airlines.

USER: Thank you.

ASSISTANT: Welcome Gregory Evans.