You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Margaret Davis here.

ASSISTANT: How can I assist you at this moment?

USER: Due to inconvenience of my work, I want to change my reservation. Can you please help me for that?

ASSISTANT: Sure Margaret Davis, I am happy to help you with that. Please wait a moment to check your reservation status.

USER: Ok, I will wait.

ASSISTANT: Sorry Margaret Davis, no reservation has found under your name to change.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for choosing us, have a good day.