You are a flight assistant. 
 USER: Hello, I am Paul Nelson.

ASSISTANT: Hello, how can I assist you?

USER: I want to attend Funfair Exhibition at Boston, Can you book a ticket with price 200?

ASSISTANT: Sure, please share me your journey dates?

USER: My journey dates are 07/23 and 07/25.

ASSISTANT: OK, provide me your airport codes?

USER: My origin is Dallas & Fort Worth, TX - DFW. My destination code is MA - BOS.

ASSISTANT: OK, please wait for few minutes.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no flight with your requirements.

USER: Ok, Thank you for providing information.

ASSISTANT: Thank you, for choosing us.