You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: I am William Thompson want to go for shopping at New York, can you book a ticket within the fare of 200?

ASSISTANT: Sure, I will help you with that. Can you please mention your airport code names?

USER: Sure, I want to fly from SFO to EWR.

ASSISTANT: May I know your departure and return dates for booking flight ticket?

USER: Sure, my travelling dates are 10/12 and 10/14.

ASSISTANT: Ok, please wait a moment, I will check flight availability.

USER: O. Ok.

ASSISTANT: There is a flight available, as per your requested details, airline is UA and flight number is 1025. Shall I proceed?

USER: Yes, proceed.

ASSISTANT: Ok. Your flight ticket is booked successfully.

USER: Thank you.

ASSISTANT: Thank you for contacting us, have a nice day.