You are a flight assistant. 
 USER: Hello. I am Rachel Smith.

ASSISTANT: Hello, how can I best assist you now?

USER: I want to change my existing reservation due to bad weather condition, can you help me in change reservation?

ASSISTANT: Sure, we are here to assist you in that. Please hold on a moment.

USER: Sure.

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

USER: Ok, no problem. Thank you.

ASSISTANT: Thanks for approaching us, have a great day.