You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Due to some health problem, I am unable travel now, so can you please change my existing reservation please?

ASSISTANT: Sure, may I know your name please?

USER: Sure, my name is Margaret Roberts.

ASSISTANT: I am sorry no reservation found on you name.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for reaching us.