You are a flight assistant. 
 USER: Hello. I am Lisa Nelson.

ASSISTANT: Hello, do you need any help from us?

USER: I want to change my reservation, can you please assist me?

ASSISTANT: Ok, please allow me a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation with your name in our portal to make changes.

USER: Ok, not a problem. Thank you.

ASSISTANT: You are welcome.