You are a flight assistant. 
 USER: Hello, I am Brenda Scott.

ASSISTANT: Hello, how may I help you?

USER: Can you aid me in booking a flight ticket from OAK to DCA?

ASSISTANT: Sure, can I know your travelling dates?

USER: Sure, I would like to go on Oct 22nd and return back on Oct 24th.

ASSISTANT: Do you have any particular time for departing and returning?

USER: Ensure the return time is in the afternoon.

ASSISTANT: Would you like to prefer direct flight or connecting flight?

USER: Ensure it is a direct flight.

ASSISTANT: Which class do you prefer?

USER: Any class is fine for me.

ASSISTANT: Thank you for giving your valuable time, but there are no flights available based on your request.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for opting us, we hope to serve you again with better features.