You are a flight assistant. 
 USER: Hello. I am Jerry Smith.

ASSISTANT: Hello. How may I guide you today?

USER: I am planning to change an existing reservation, due to health issue. Can you please help me out?

ASSISTANT: Yes, I can help you.

USER: Thank you.

ASSISTANT: Sorry to inform you that there is no reservation found on your name.

USER: That's fine. Thank you for your service.

ASSISTANT: Thank you for reaching us.