You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Can you help me in booking a flight ticket from SFO to DCA?

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

USER: I want to travel on 12/18, and return on 12/20.

ASSISTANT: May I know your connection limit?

USER: I need a direct flight.

ASSISTANT: Is there any class preference for you?

USER: I am comfortable with any class.

ASSISTANT: Do you have any other specifications?

USER: No.

ASSISTANT: Your good name please.

USER: I am Cynthia Gonzalez.

ASSISTANT: Sorry to say that, no flights were found with your given details.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Thank you for reaching us.