You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I know how best I can help you today?

USER: Myself Carolyn Hill, I am willing to change my existing reservation. Can you please help me for this?

ASSISTANT: Sure, please wait. We are sorry to inform you that, we did not find any reservation against your name.

USER: Not a big deal, anyway thank you very much for your service.

ASSISTANT: You are welcome.