You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I want to travel from BOS to DEN. Can you help me to book a flight ticket?

ASSISTANT: Sure, can you share your journey dates?

USER: I want to fly in the flight on Feb 27 and Feb 29.

ASSISTANT: Do you have any preferences?

USER: I want to depart in evening time.

ASSISTANT: May I know your name?

USER: I am Emily Rodriguez.

ASSISTANT: Sorry, there is no flight on your given dates.

USER: That's ok. Anyways, thank you.

ASSISTANT: Thank you for reaching us.