You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you today?

USER: Lisa Evans here. I already have an reservation to attend a meeting, due to some problems meeting place has been changed. So I need a few changes in my reservation,. So please change my reservation.

ASSISTANT: Sure, I am here to help you.

USER: Ok.

ASSISTANT: Sorry Evans, there is no reservation found as per your name to modify your reservation.

USER: That's ok, thank you.

ASSISTANT: You are welcome.