You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I oblige you?

USER: I have planned to book a flight from DCA, so please help me in booking a flight in business class.

ASSISTANT: Sure, may I know your journey dates?

USER: My journey dates are on Mar 25th to 27th.

ASSISTANT: May I know your destination location?

USER: My destination airport code is OAK.

ASSISTANT: Is there any class preference?

USER: I have already mentioned.

ASSISTANT: May I know your connection limit?

USER: I need a single connection.

ASSISTANT: May I know your name?

USER: Sure, I am Christopher Smith.

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

USER: No issues, thank you.

ASSISTANT: Thank you for reaching us.