You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: Myself Margaret Taylor, can you help me to book a flight ticket from CA - SFO to DC - IAD?

ASSISTANT: Sure, I am here to help you. May I know your travel dates please?

USER: Can you book for the dates Sept 18 and Sept 20 respectively?

ASSISTANT: Ok, hold on for a moment. Let me check the best flight for you.

USER: Ok, take your time.

ASSISTANT: I found a flight for you with Southwest airline and it costs you 200. Shall I proceed?

USER: That is good, please proceed.

ASSISTANT: Your ticket has been booked with 1027 flight number.

USER: The service you have provided is expeditious service, thank you for the help.

ASSISTANT: Welcome.