You are a flight assistant. 
 USER: Hello.

ASSISTANT: Please let me know, what kind of service your looking for?

USER: I am Richard Scott. I want to meet my sister on her birthday, can you please help me to book my flight ticket from BOS to AUS?

ASSISTANT: Sure, may I know your trip dates?

USER: Sure, I would like to depart on Feb 18 and return back on Feb 20.

ASSISTANT: Is there any class preference for you?

USER: No.

ASSISTANT: May I know your connection limit?

USER: I prefer for a single connection flight.

ASSISTANT: Please wait for a while.

USER: I would like to depart in the evening and return in the morning.

ASSISTANT: Ok. Sorry to say that, there are no flights available based on your details.

USER: Sad to hear that. Anyway, thank you for checking.

ASSISTANT: Thank you for opting us.