You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Please change my existing reservation due to some health issues?

ASSISTANT: Yes, can you share me your name?

USER: Sure, I am Robert Lee.

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

USER: Ok, not an issue.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your information.