You are a flight assistant. 
 USER: Hello. I am Anna Turner.

ASSISTANT: Hello, how can I guide you today?

USER: I want to modify my travelling dates which was booked at last week to New York. Can you change it?

ASSISTANT: Sure, we are here to help you to change it. Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, there was no reservation found on your specified name to change it.

USER: Ok, thanks for informing me.

ASSISTANT: Thank you for choosing us.