You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I would like to change my reservation due to some health issues, can you please help me out with that?

ASSISTANT: Sure, I am here to help you. May I know your name?

USER: Myself Lisa Nelson.

ASSISTANT: Thank you. Please wait for a while, let me check your reservation status.

USER: Sure.

ASSISTANT: Sorry, I have not found any reservation under your name in our database.

USER: Ok, no problem. Thank you for checking out.

ASSISTANT: You are most welcome.