You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

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

ASSISTANT: Sure, may I know your name?

USER: Myself Lisa Green.

ASSISTANT: Sorry to say, no reservation found on your name.

USER: No problem, thanks for checking.

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