You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Mark Roberts.

ASSISTANT: How may I serve you?

USER: As I need to play for the upcoming football tournament, I would like to travel from Boston, BOS. Can you help me in book a flight ticket?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Can I have your landing airport code?

USER: My landing airport code is JFK.

ASSISTANT: Please, let me know your scheduled trip dates.

USER: My travelling dates are 12/21 and return on 12/23.

ASSISTANT: How much should be your ticket price?

USER: I can pay up to 200.

ASSISTANT: Thank you for sharing the details.

USER: Ok.

ASSISTANT: I am sorry to inform you that, there are no flights available that matches your requirements.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for availing us.