You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Emily Carter.

ASSISTANT: How can I aid you?

USER: I want to attend an event in San Francisco. Can you help me to book a ticket from DCA to SFO?

ASSISTANT: Sure, may I know your trip dates?

USER: I want to fly on 12/21 and 12/23.

ASSISTANT: There is  a direct flight with number 1004, the fare is 200 in airline Frontier. Can I book it?

USER: Proceed to booking.

ASSISTANT: Your ticket is reserved.

USER: Thank you for your help.

ASSISTANT: Thank you for booking.