You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I be your helping hand?

USER: I am Stephanie Thomas. I am planning to go for Brooklyn walking tour at New York, EWR with my friends. Can you please book a ticket for me?

ASSISTANT: Sure, may I know your source code?

USER: Source code is San Francisco, SFO.

ASSISTANT: May I know your travelling dates?

USER: Journey dates are 01/25 to 01/27.

ASSISTANT: Sorry, there is no flight available to your destination.

USER: No problem. Thank you.

ASSISTANT: Thank you.