You are a flight assistant. 
 USER: Hello, John Moore here.

ASSISTANT: Hello, how can I help you?

USER: Due to some issue in my office I cannot go on the trip which is I have planned earlier. Can you please help to change it?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Please wait a moment, I will check your details and get back to you.

USER: Ok.

ASSISTANT: Sorry to inform you that there is no active reservation found on your name to proceed further.

USER: It's ok, thank you anyway.

ASSISTANT: Thank you for reaching us.