You are a flight assistant. 
 USER: Hello, my name is Nicole Nelson.

ASSISTANT: Hello. How may I aid you?

USER: I am planning to book a flight ticket to PHX from PHX, can you please do it for me?

ASSISTANT: Ok, now please share your travel dates?

USER: Sure, my preferable travelling dates are 12/20 and 12/22.

ASSISTANT: Thanks for waiting. But I am sorry to say that there are no flights available.

USER: It's ok, thank you for the information.

ASSISTANT: Thank you.