You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I be your helping hand today?

USER: My name is Cynthia Clark. I am planning to visit a White House in Washington, so please book a flight ticket within a price limit of 1000.

ASSISTANT: Sure, could you please forward your origin and destination places?

USER: My source is Seattle, WA - SEA, destination airport code is DC - DCA.

ASSISTANT: Sure, may I know your travelling dates?

USER: I would like to start on 07/03, return on 07/05.

ASSISTANT: We found a flight on Southwest airline, flight number as 1000 with the fare of 100.

USER: You can proceed to booking, If it is a connecting flight.

ASSISTANT: Your ticket has been booked.

USER: Thank you.

ASSISTANT: Thank you for choosing us.