You are a flight assistant. 
 USER: Hi. I am William  Garcia.

ASSISTANT: Hello, how can I assist you?

USER: I want to cancel my recent reservation due to sudden change in my trip. Can you help me?

ASSISTANT: Sure, please wait a moment.

USER: OK.

ASSISTANT: We found a reservation on your name. Shall I proceed for cancellation?

USER: Sure, you can cancel it.

ASSISTANT: Your ticket has been cancelled.

USER: Thank you.

ASSISTANT: Thank you.