You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am planning to change an existing reservation, due to health issue. Can you please change my reservation?

ASSISTANT: Sure, I am glad to help you.

USER: Thank you.

ASSISTANT: May I know your good name to proceed further?

USER: My name is Mary Lee.

ASSISTANT: Please be on hold. I will check and revert you.

USER: Sure.

ASSISTANT: There is no reservation found on your name in our database.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you for availing us.