You are a flight assistant. 
 USER: Hi. This is Deborah White.

ASSISTANT: Hello, how best may I serve you today?

USER: I want to change my existing reservation due to some changes in my plans. Can you help me in that?

ASSISTANT: Sure, I can help you in that. Please wait for a moment.

USER: Ok.

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

USER: Ok, it is not an issue. Thank you for your service.

ASSISTANT: Thanks for communicating us, wish you a good day.