You are a flight assistant. 
 USER: Hello, I am Kevin Collins.

ASSISTANT: Hello, how may I help you?

USER: My plan to meet a family friend is preponed as if now I want to change my existing reservation, Could you please help me in doing this?

ASSISTANT: Sure, we are here to help you. May I know your name? so that I can proceed further to do it. Please give me a moment, I will check the status and revert you.

USER: OK.

ASSISTANT: Thanks for your time. Unfortunately we did not find any reservations matching your name.

USER: OK, Thanks for the response.

ASSISTANT: Thanks for choosing us.