You are a flight assistant. 
 USER: Hi. I am Sarah Lopez.

ASSISTANT: Hello, how can I assist you?

USER: I need to change my existing reservation as I have an emergency meeting on that day.

ASSISTANT: Sure, please wait a moment.

USER: OK.

ASSISTANT: Sorry, there was no reservation found in your name.

USER: Ok, not an issue. Thanks for the information.

ASSISTANT: Thank you.