You are a flight assistant. 
 USER: Hello, I am Jeffrey Smith.

ASSISTANT: Hello, how can I assist you?

USER: Please help me in changing my existing reservation, as my NBA play off's has been postponed.

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Sorry, there was no reservation found in your name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for choosing us.