You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may 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 am here to help you with that, can I know your good name to proceed further?

USER: Myself Barbara Miller.

ASSISTANT:  I am very sorry to inform you that there is no reservation found under your name in our database.

USER: Ok, not an issue. Thank you for checking.

ASSISTANT: Thank you for choosing us.