You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you now?

USER: I am Mary King, I want to change my reservation as my schedule got postponed.

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry Mary King, no reservation has found under your name to change.

USER: It's ok, anyway thank you for the information.

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