You are a flight assistant. 
 USER: Hi, Shirley Lewis here.

ASSISTANT: Hello, how may I help you?

USER:  I planned to attend for my parents 27th wedding anniversary in DTW, can you book the flight ticket from AUS?

ASSISTANT: That's so sweet, may I know your journey dates?

USER: Sure, my dates are from 06/02 to 06/04.

ASSISTANT: Wait for a while.

USER: Ok.

ASSISTANT: Sorry to say that there is no airline providing service on those dates, Lewis.

USER: That's fine. Thank you for your information.

ASSISTANT: Thank you for choosing us.