You are a flight assistant. 
 USER: Hello. Stephanie Moore here.

ASSISTANT: Hello, may I know which service you are looking for?

USER: I would like to change my existing reservation, can you help me for that because I have some work in my hometown.

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Sorry for the inconvenience, I haven't found any existing reservation in our database with your name.

USER: Ok, that's fine. Thank you for your services.

ASSISTANT: Thank you for consulting us.