You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: Can you please change my reservation due to some health issues?

ASSISTANT: Sure, may I know your name for the changing process?

USER: My name is Charles Hill.

ASSISTANT: Thank you, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, as per your concern I can not amend your reservation, as your reservation is not found as per our records.

USER: Ok, no issue. Thank you.

ASSISTANT: Welcome, thank you for reaching us.