You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Carolyn Martinez.

ASSISTANT: Ok.

USER: I want to change my existing reservation due important work in my home.

ASSISTANT: Sure. Wait for a minute, I will check and get back to you.

USER: Sure.

ASSISTANT: Sorry to tell that there is no reservation on your name. Thank you for approaching us.

USER: Ok, Thank you.