You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Gregory King here.

ASSISTANT: How may I guide you today?

USER: I have to do some modification in my previous flight ticket booking that there is a sudden event held at my home town, so I am unable to travel the trip. Can you please help me out with changing of my reservation?

ASSISTANT: Sure, I am glad to help you to change your reservation.

USER: Thank you for accepting my request.

ASSISTANT: Please wait a moment.

USER: Ok, take your time.

ASSISTANT: sorry, no reservation found on your name to change.

USER: Oh! I think the ticket was not booked due to server issue. Anyway, thank you for the information.

ASSISTANT: Thank you for reaching us.