You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Nancy Davis here. I would like to change my reservation due to some health issues, can you please help me in that?

ASSISTANT: Sure, please wait for a minute.

USER: Sure.

ASSISTANT: Thanks for your waiting, I could not find any reservation with your name.

USER: That's ok, no problem. Thank you for checking out.

ASSISTANT: My pleasure.