You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: Carolyn Walker here. I would like to book a ticket from BOS to SFO, can you please help me with that?

ASSISTANT: Sure, can I know the travel dates please?

USER: The travel dates are from 11/23 to 11/25.

ASSISTANT: Could you please provide the departure and return time?

USER: My depart and return time is at evening.

ASSISTANT: Do you have any requirements?

USER: No.

ASSISTANT: Sorry, there are no flights available as per your request.

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

ASSISTANT: Thank you for approaching us.