You are a flight assistant. 
 USER: Hello. I am Timothy Parker.

ASSISTANT: Hello, how can I guide you for today?

USER: I want to travel from PHX to LAS. Can you book a flight ticket for me?

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: I want to fly on 12/28 and 12/30.

ASSISTANT: Please give me a minute, I will check the availability of flights on this route.

USER: Ok.

ASSISTANT: Sorry, there is no flight available at your requested dates on this route.

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: Thank you for contacting us, have a nice day.