You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello. I am here to assist you, may I know your concern?

USER: Please book a ticket from Denver, CO-DEN to New York, NY-JFK.

ASSISTANT: Ok, I need to know your travel dates to book?

USER: Sure. My travel dates are from 05/17 to 05/19.

ASSISTANT: Sorry, there are no flight available.

USER: I am Ryan Roberts. Thank you.

ASSISTANT: Thank you for connecting with our agency.