You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: Can you help me in booking from OAK to CLT, as there is a business meeting to attend?

ASSISTANT: Sure, I am here to help you out. May I know your travelling dates please?

USER: My trip dates are Jan 13 to Jan 15.

ASSISTANT: Can you please share your connection limit?

USER: I am looking for a stopover flight which return in evening.

ASSISTANT: Is there any class preference?

USER: No.

ASSISTANT: May I know your name please?

USER: I am Helen Lee.

ASSISTANT: Do you have any other specification?

USER: No.

ASSISTANT: Helen Lee, there are no flights available in your route.

USER: No issue, thank you.

ASSISTANT: Thank you for choosing us.