You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Can you please book a flight ticket from SFO to DEN?

ASSISTANT: Let me know your travelling dates.

USER: Thank you for that. I have planned my travel dates as Nov 25 and Nov 27.

ASSISTANT: Can I know your name?

USER: Sure, myself Brandon Jackson.

ASSISTANT: Sorry, no flights found for your travelling dates.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: Thank you.