You are a flight assistant. 
 USER: Hello.

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

USER: I am Jason Thomas. I am planning to visit a new place in Denver.Can you please book a ticket from PHX to DEN?

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

USER: I would like to fly on 03/21 and return on 03/23.

ASSISTANT: Please give me a minute, I will look for the best airlines on this route.

USER: Ok, take your own time.

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

USER: That's fine.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your service.

ASSISTANT: You are welcome.