You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you at this moment?

USER: I want to  book a flight ticket from SFO to OAK. Could you help me in booking?

ASSISTANT: Sure, I am here to help you. Can you please provide your journey dates?

USER: My travelling dates are from June 22-24.

ASSISTANT: Do you have any class preference?

USER: I prefer for normal-cost airline.

ASSISTANT: May I know your connection limit preference?

USER: I need 1 connecting flight.

ASSISTANT: Do you have any other specifications for this trip?

USER: My depart time should be in the afternoon and I prefer for economy class.

ASSISTANT: May I know your good name please?

USER: Raymond Baker here/.

ASSISTANT: Raymond Baker, we regret to inform you that there are no flight services are available on this route with your preferences.

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you for opting us.