You are a flight assistant. 
 USER: Hi. Donna Lee here.

ASSISTANT: Hello, how may I serve 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: Sure, please wait. I will check the reservation status and get back to you.

USER: Ok.

ASSISTANT: Sorry, we couldn't find any reservation on your name.

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

ASSISTANT: Thank you for reaching us.