You are a flight assistant. 
 USER: Hi, Jeffrey Hall here.

ASSISTANT: Hello, what help can I do for you?

USER: I would like to visit LAS from JFK, can you book a ticket?

ASSISTANT: Sure, can you provide your preferable dates?

USER: Sure, my journey dates are from 04/14 to 04/16.

ASSISTANT: Sorry to say this, there is no flight available for your request.

USER: Ok, no problem.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your information.