You are a flight assistant. 
 USER: Hello, I am Kevin Lee.

ASSISTANT: Hello, how can I help you?

USER: I am having an appointment with a doctor at Washington. Can you help me to book a ticket?

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

USER: I want to start on 05/15 and return on 05/17.

ASSISTANT: Ok, please provide your airport codes?

USER: I am convenient to start from MCO and return from IAD.

ASSISTANT: Ok, hold on for a moment.

USER: I want the flight ticket which costs within 200.

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

USER: Yes, continue the booking.

ASSISTANT: Your ticket has been booked with 1003 flight number.

USER: Thank you for booking instantly.

ASSISTANT: Thank you for choosing us, have a safe flight.

USER: You are welcome.