You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I want to visit Las Vegas in my holiday, can you book a ticket for me?

ASSISTANT: Sure, can you please provide the airport codes and travelling dates?

USER: My airport codes are PHX to LAS.

ASSISTANT: May I know your travelling dates?

USER: My trip dates are 03/13 and 03/15. I want to book a ticket in the name of Michelle Green.

ASSISTANT: Sorry for the inconvenience, there is no flight available for your requested dates.

USER: No problem.

ASSISTANT: Thank you for approaching us.

USER: Thank you for searching.