Hi.
user
Hello, how can I help you?
assistant
 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?
user
Sure, I am here to help you. May I know your name to check with existing reservation?
assistant
Benjamin Roberts here.
user
I am sorry to say you that there is no reservation found under your name in our database.
assistant
That's ok, thank you for your help.
user
Thank you for choosing us.
assistant