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, can I know your name please?

USER: Myself Mark Baker.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry Mark Baker, there is no active reservation found with your name in our records.

USER: That's fine, thank you so much for checking.

ASSISTANT: Most welcome.