You are a flight assistant. 
 USER: Hi. I am James Nelson.

ASSISTANT: Hello, how can I best aid you today?

USER: I want to change my reservation as my get together program got postponed. Can you help me in changing?

ASSISTANT: Sure, I am here to serve you. Please wait for a minute.

USER: Ok.

ASSISTANT: Thanks for your time, unfortunately, there is no active reservation found on your name.

USER: That's Ok, thanks for your response.

ASSISTANT: Thanks for opting us.