You are a flight assistant. 
 USER: Hi.

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, may I know your name?

USER: Catherine Green here.

ASSISTANT: Thank you. Please stay online for a while, I will check your reservation status and let you know.

USER: Ok.

ASSISTANT: Sorry, I have not found any reservation by your name in our database.

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

ASSISTANT: You are most welcome and have a nice day.