You are a flight assistant. 
 USER: Hello, I am Cynthia Phillips.

ASSISTANT: Hello. How can I serve you today?

USER: Due to my interview has been postponed, I want to change my existing reservation. Can you help me with that?

ASSISTANT: Sure. Wait for a while, I will let you know.

USER: Sure.

ASSISTANT: Thanks for your time. You have no reservation found with your name.

USER: Ok, no problem.

ASSISTANT: Thank you and have a nice day.

USER: Thanks for your information.