You are a flight assistant. 
 USER: Hello. I am Sandra Perez from Atlanta.

ASSISTANT: Hello, what can I do for you at this time?

USER: Could you help me in booking a flight ticket to Boston on 12/17?

ASSISTANT: Sure, I am at your service. May I know from where you would like to start?

USER: I would like to start from GA - ATL.

ASSISTANT: When are you planning to return from your trip to Boston?

USER: I want to return on 12/19.

ASSISTANT: Please help me with your destination airport code.

USER: My destination airport code is MA - BOS.

ASSISTANT: Thank you for the detail, please wait for a while.

USER: Sure.

ASSISTANT: Looks like there are no flights on your requested dates. I am sorry for that.

USER: No problem, thank you.

ASSISTANT: Thank you for checking with us.