You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I am William Anderson. I am planning to attend music concert at JFK, can you please help me with booking a flight ticket from DEN?

ASSISTANT: Sure, can you share your trip dates?

USER: Sure, I would like to take off on Jan 3 and return on Jan 5.

ASSISTANT: Do you have any preferences?

USER: I would like to return during afternoon time.

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

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thank you for reaching us.