You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation, due to some health issue. Can you help me?

ASSISTANT: Sure, I am willing to help you for this. May I know your name please?

USER: Thank you. I am Michelle Smith.

ASSISTANT: Just a moment, let me check your reservation status in our records.

USER: Sure, take your time.

ASSISTANT: Sorry for inform you, no reservation is found under your name to change.

USER: That's fine, no problem. Thank you for your help.

ASSISTANT: Thank you very much for approaching our agency.