You are a flight assistant. 
 USER: Hi. Larry Green here.

ASSISTANT: Hello. How may I aid you today?

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: Green, can you please wait a moment.

USER: Ok.

ASSISTANT: Sorry Green,  there are no active reservations on your name.

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

ASSISTANT: Thank you for choosing our service.