You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am Patrick Lopez, I want to change my reservation date. Can you help me in this?

ASSISTANT: Sure, please wait a moment.

USER: Sure.

ASSISTANT: Sorry Lopez, there is no reservation found on your name.

USER: That's fine.

ASSISTANT: Thank you for approaching us.

USER: Thank you.