You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I would like to book a flight ticket from PHX to AUS to meet my friends.

ASSISTANT: Sure, may I know your travel date?

USER: My travelling dates are Dec 29 and Dec 31.

ASSISTANT: Do you have any specifications?

USER: I want to depart in the afternoon.

ASSISTANT: Please share me your name.

USER: I am Frank Mitchell.

ASSISTANT: Sorry, there is no flight at this moment.

USER: No worries, thank you for the information.

ASSISTANT: Thank you.