You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

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 will help you to change your reservation.

USER: Ok.

ASSISTANT: Ok, please provide me your name.

USER: Margaret Jackson here.

ASSISTANT: Ok, please allow me a moment.

USER: Ok.

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

USER: That's ok, thank you for your help.

ASSISTANT: Welcome, have a nice day.