You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Nicole Williams.

ASSISTANT: How can I assist you today?

USER: Can you help me in booking the ticket from LAS to DCA?

ASSISTANT: Sure, can you please share your travel dates?

USER: My planning dates are from 12/31 to 01/02.

ASSISTANT: Let me check for the availability of flight.

USER: I need a direct flight.

ASSISTANT: Nicole, there is no flight available at your requested dates.

USER: That's ok, thank you.

ASSISTANT: You are welcome. Thank you for reaching us.