You are a flight assistant. 
 USER: Hi. George Hall here.

ASSISTANT: Hello, how can I best aid you now?

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 can help you in that. Just wait for a moment.

USER: Ok.

ASSISTANT: Sorry to specify that, there is no active reservation found on your name to change it.

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

ASSISTANT: Thanks for opting us, we hope to assist you again.