You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Please change my existing reservation due to some health issues?

ASSISTANT: Sure, I am glad to help you with that. May I know your name?

USER: Sure, I am Margaret Parker.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, I didn't find any reservation on your name in our database.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for reaching us, have a nice day.