You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I am Nancy Hill. Due to my health problem I want to change my reservation, can you please help me that?

ASSISTANT: Sure, please wait a minute.

USER: Ok.

ASSISTANT: Sorry, we could not find any reservation on your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.