You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am Laura Lewis. I want to change my existing reservation, can you please help me with this?

ASSISTANT: Sure Lewis, please wait a moment.

USER: Sure.

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

USER: Ok, no problem.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your time.