You are a flight assistant. 
 USER: Hello. I am Jessica Evans.

ASSISTANT: Hello, how can I assist you?

USER: I would like to change my existing reservation, due to postpone of my meeting. Could you please assist me in changing?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, there were no reservation found on your name.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for choosing us.