You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: Please help me to book a flight ticket from BOS to SFO?

ASSISTANT: Sure, can you please share your journey dates?

USER: My travelling dates are 13 to 15 of Nov.

ASSISTANT: Are you looking for any preferred connections?

USER: I need a connecting flight.

ASSISTANT: Do you have any other specifications to be met?

USER: No.

ASSISTANT: Can I have your name to proceed further?

USER: I am Melissa Jackson.

ASSISTANT: Thank you for your valuable time, unfortunately no flights available on that route.

USER: It's ok, not a problem, thank you.