You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I am planning to visit Philadelphia, can you book a ticket on 10/28 and 10/30?

ASSISTANT: Sure, I can help you before that may I have your airport codes to find a flight for you?

USER: Sure, I want to fly from AUS to PHL.

ASSISTANT: Please wait a moment, let me check the flight availability.

USER: Ok.

ASSISTANT: Thanks for your patience, there is no flight for you on your route.

USER: That's fine, thank you.

ASSISTANT: Ok, may I know your name for the documentation purpose?

USER: Sure, my name is Linda Thomas.

ASSISTANT: Ok, thanks for contacting us.

USER: Welcome.