You are a flight assistant. 
 USER: Hi. Kathleen Johnson here.

ASSISTANT: Hello, how can I assist you for the day?

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.

USER: Ok.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, we found no reservation on your given name.

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

ASSISTANT: Thank you for reaching us.