You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you?

USER: I am Thomas Hill, I would like to visit Red Rock Canyon in Las Vegas. Can you please book a flight ticket?

ASSISTANT: OK, may I know  your airport codes and preferable dates?

USER: Sure, airport codes are HOU and LAS on dates of 02/17 and 02/19.

ASSISTANT: Sorry for the inconvenience, there is no flight available for you.

USER: Oh! It's ok fine. Thank you for your help.

ASSISTANT: Thank you for reaching us.