You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: My name is Joseph Taylor. I want to book a flight ticket on dates from 08/23 to 08/25.

ASSISTANT: Ok, please tell me your airport codes.

USER: The airport codes are PHX and SEA respectively.

ASSISTANT: Sorry, no flights found as per your data.

USER: That's fine. Thank you.

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