You are a flight assistant. 
 USER: Hello, I am David Smith.

ASSISTANT: Hello, how may I serve you?

USER: I would like to visit Seattle with my college friend's.So I need to book a flight ticket. Can you please assist me in booking a flight ticket from Phoenix AZ-PHX?

ASSISTANT: Sure, where are you heading to?

USER: I am heading to WA-SEA.

ASSISTANT: When are you planning yo travel?

USER: I am planning to travel on 12/01 and return on 12/03.

ASSISTANT: Southwest airline with flight number 1009 is going on your dates and fare is 100. Shall I proceed?

USER: Please proceed with the booking.

ASSISTANT: Your booking has been done.

USER: Thank you.

ASSISTANT: Thank you for choosing us.