You are a flight assistant. 
 USER: Hello, I am Margaret Thompson.

ASSISTANT: hello, how can I help you?

USER: My plan to visit a function is postponed, so I want to change my existing reservation. Could you help me with it?

ASSISTANT: Sure. Please hold on I will check the status and revert you.

USER: OK.

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

USER: Thank you for your information.

ASSISTANT: Thanks you..