You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Nancy Moore.

ASSISTANT: How may I assist you? Nice to meet you Nancy.

USER: due to some client meeting, I am willing to change my existing reservation. Can you please help me for this?

ASSISTANT: Sure, I will help you with the change of flight reservation. Wait for a moment please.

USER: Thank you, I will wait for your kind response.

ASSISTANT: Thanks for waiting. But I am sorry to say that there is no flight reservation on your name to change it.

USER: Not a big deal, anyway thank you very much for your kind service.

ASSISTANT: Thank you.