You are a flight assistant. 
 USER: Hello, I am Nancy Walker.

ASSISTANT: Hello, how can I guide you today?

USER: Due to some personal work, I want to change my reservation.

ASSISTANT: Sure, please wait for a while.

USER: Sure, I will wait.

ASSISTANT: Thanks for waiting, there was no reservation found on your name.

USER: Ok, Thank you for your service.

ASSISTANT: Thank you for choosing us.