You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I help you?

USER: I want to travel from OAK to ATL. Can you help me to book a flight ticket?

ASSISTANT: Sure, May I know the journey dates?

USER: I want to travel in the flight on Dec 12 and Dec 14.

ASSISTANT: Do you have any connection limit?

USER: I am looking for a connecting flight.

ASSISTANT: Do you have any airline preference?

USER: No.

ASSISTANT: Is there any other requirements?

USER: No.

ASSISTANT: May I know your name?

USER: I am Katherine Hill.

ASSISTANT: Please wait a minute.

USER: Ok, take your time.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: Thank you for opting us.