You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I oblige you today?

USER: I want to change my existing reservation, due to sudden meeting at my office on my boarding day. Can you please aid me to change it?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: May I know your name to proceed further?

USER: Sure, my name is Brandon Thomas.

ASSISTANT: Please wait for a moment, I will check the status and revert to you.

USER: Sure, I will wait.

ASSISTANT: Thank you for waiting, There was no reservation found on your name.

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

ASSISTANT: Thank you for choosing us.