You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Anna Smith. I would like to book a flight ticket from PHL to AUS.

ASSISTANT: Sure, can I know your preferable dates?

USER: I am planning to start on 08/23 and return back on 08/25.

ASSISTANT: Sorry, no flights available.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you for reaching us.