You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: I am Kenneth Wilson. I want to change my reservation due to health problem, can you hep me?

ASSISTANT: Sure, I am here to help you out. Please allow me a moment.

USER: Sure.

ASSISTANT: Sorry Kenneth Wilson, there is no active reservation. Thank you for reaching us.

USER: No problem, thanks for checking.