You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Please book a flight ticket from SFO to DCA?

ASSISTANT: Sure, let me know your travel dates please?

USER: My journey dates are Nov 29 and Dec 01.

ASSISTANT: May I know your connection limit?

USER: I need a direct flight.

ASSISTANT: Do you need any other preference?

USER: No.

ASSISTANT: Can I know your name please?

USER: I am Nancy Wilson.

ASSISTANT: Sorry to inform you that there are no flight services available on your given details.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for contacting us.