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

ASSISTANT: Hello, how can I assist you today?

USER: last week I was going to attend, a dinner hosted by President Trump. But the dates have been changed. So, please cancel my reservation.

ASSISTANT: Sure, please wait for a moment. I will check the availability of reservation  on your name and revert you. Thank you for waiting, we found a reservation on your name, shall I proceed for cancellation?

USER: Yes, please.

ASSISTANT: Thank you for choosing us, your ticket has been cancelled.

USER: Thanks for the help.