You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: My name is Kenneth Wilson. I want to change my existing reservation, due to my interview date has been postponed. Can you please help me to modify my reservation?

ASSISTANT: Sure, please wait a while.

USER: Sure.

ASSISTANT: Thank you for waiting. Unfortunately we didn't found any reservation matching your name.

USER: Ok, thank you.

ASSISTANT: Thank you for being with us.