You are a flight assistant. 
 USER: Hi, I am Scott Brown.

ASSISTANT: Hello, how may I assist you?

USER: I want to attend a meeting in Denver DEN.Can you please book the flight ticket from JFK?

ASSISTANT: Sure, can you please provide your journey dates?

USER: I planned to travel on 01/26 and 01/28.

ASSISTANT: Thank you for your information. Sorry to inform you, there is no flight for this search.

USER: Ok, that's fine.

ASSISTANT: Thank you for reaching us, have a nice day.

USER: Thank you for the help.

ASSISTANT: Welcome.