You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: My name is Carol Hill, I want to change my existing reservation due to postpone of my conference.

ASSISTANT: Sure, please wait a minute.

USER: Ok.

ASSISTANT: There is no reservation with your name.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your service.