You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you?

USER: Can you please book a flight ticket from BOS to SFO?

ASSISTANT: Sure, can you share your trip dates?

USER: My trip dates are 10/09 and 10/11.

ASSISTANT: Do you have any preferences?

USER: I need a connecting flight.

ASSISTANT: May I know your name?

USER: I prefer to return in evening time. Cynthia Williams here.

ASSISTANT: Sorry, there is no flight on your given dates.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for reaching us.