You are a flight assistant. 
 USER: Hello, I am Michael Brown.

ASSISTANT: Hello. How can I help you?

USER: Can you aid me in booking a flight ticket from PHL to AIS?

ASSISTANT: Sure, I will help you to book a flight. Can you please share me your travelling dates?

USER: Sure, I would like to go on 11/28 and return back on 11/30.

ASSISTANT: Ok, please provide me your correct destination airport code?

USER: My destination airport code is AUS.

ASSISTANT: Sorry, no flights are available on your route.

USER: That's ok, thank you for checking.

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