You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you today?

USER: Help me in booking a flight from OAK to SFO?

ASSISTANT: Sure, please share me your trip dates.

USER: My travelling dates are Sept 15 to 17.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I prefer connecting flight.

ASSISTANT: For booking, we need your good name. Please mention it.

USER: I am Shirley Lopez.

ASSISTANT:  Is there any other specifications?

USER: No.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: That's ok, thank you.

ASSISTANT: Thank you for choosing us.