You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you for the day?

USER: Can you please help me to book a flight ticket from SFO to DCA?

ASSISTANT: Can you please share your travelling dates?

USER: My travelling dates are Nov 29 to Dec 1.

ASSISTANT: Do you prefer class?

USER: I would like to prefer business class.

ASSISTANT: Do you need connection limit?

USER: I need a direct flight.

ASSISTANT: May I know your name?

USER: My name is Rebecca Nelson.

ASSISTANT: Sorry, no flight found in that route.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for reaching us.