You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Please help me to book a flight ticket from IAD to OAK.

ASSISTANT: Sure, may I know your planned trip dates?

USER: My trip dates are from Mar, 03 to Mar, 05.

ASSISTANT: Is there any connection limit?

USER: I need a single connecting flight.

ASSISTANT: May I know your class preference?

USER: I prefer business class.

ASSISTANT: Can you please share your arrival and depart timings?

USER: No, I do not have.

ASSISTANT: Do you have any other specifications?

USER: No.

ASSISTANT: Please forward your name.

USER: I am Anna Martin.

ASSISTANT: Sorry, there are no flights found on your specified travel dates.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for availing us.