You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you today?

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

ASSISTANT: Please provide your trip dates.

USER: Sure, I want to travel on Apr 13 and need to return on Apr 15.

ASSISTANT: Do you need any connection limit?

USER: I need a flight with single connection.

ASSISTANT: Is there any other specifications?

USER: My depart time must be in the evening.

ASSISTANT: May I know your name?

USER: I am Virginia Parker.

ASSISTANT: There are no flights available on your routes.

USER: Ok, not an issue. Thank you for checking.

ASSISTANT: Thank you for choosing us.