You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I be of your assistance?

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

ASSISTANT: Sure, I am here to help you. Please wait a minute.

USER: Sure.

ASSISTANT: Thanks for waiting. There is no reservation on your name.

USER: No problem, thanks for checking.

ASSISTANT: Thank you.