You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello.

USER: I am Katherine Smith.

ASSISTANT: How may I assist you?

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

ASSISTANT: Sure, please mention your travelling dates to get a flight for you.

USER: Departure date is 06/22 and 06/24 is return date.

ASSISTANT: Sorry to inform you, there is no flight on your route.

USER: Thanks for the help.

ASSISTANT: Welcome.