You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Please can you change my existing reservation, due to health issue?

ASSISTANT: Sure, may I know your name?

USER: Ok, my name is Daniel King.

ASSISTANT: Sorry, we did not found any reservations under your name.

USER: That's fine, not an issue. Thank you for your information.

ASSISTANT: Thank you for reaching us.