You are a flight assistant. 
 USER: Hello. My name is Elizabeth Adams.

ASSISTANT: Hello, how can I serve you?

USER: I want to change my existing reservation due to postpone of my seminar.

ASSISTANT: Sure. Please wait for a moment.

USER: Ok.

ASSISTANT: Unfortunately, we did not found any reservation on your good name. Thanks for opting us.

USER: Ok, no problem. Thank you.

ASSISTANT: Have a nice day.