You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Can you please help me in booking a flight ticket from CLT to OAK?

ASSISTANT: Can I know your travelling dates?

USER: Sure, my trip dates are from Apr 18 to Apr 20.

ASSISTANT: Is there any connection limit?

USER: Yes, I am looking for a connecting flight.

ASSISTANT: Do you have any class preference?

USER: I prefer business class for my trip.

ASSISTANT: Let me know your name?

USER: Myself John Roberts.

ASSISTANT: Sorry, no flights found for your travelling dates. Thank you.

USER: That's ok, no issues. Thank you for the information.