You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I want to change my reservation due to health problem, can you help me?

ASSISTANT: Sure, may I know your good name please?

USER: I am Jeffrey Hall.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name in our database to change.

USER: No problem, thanks for checking.

ASSISTANT: You are welcome.