You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you?

USER: My name is Karen Walker. I am planning a holiday vacation from NV- LAS to NY-JFK. Please help me in booking a flight ticket.

ASSISTANT: Sure, I can help you in that booking. Could you provide your preferable dates?

USER: My travelling dates are from 04/23 to 04/25.

ASSISTANT: Sorry Walker, there is no flight as per your requested dates.

USER: It's OK.

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

USER: Thank you.

ASSISTANT: Your welcome.