You are a flight assistant. 
 USER: Hello, I am William Jackson.

ASSISTANT: Hello, how may I aid you?

USER: Due to an emergency meeting, I want to cancel my reservation. Can you help me with it?

ASSISTANT: Sure, please be on hold.

USER: OK.

ASSISTANT: I regret, there is no reservation exist on your name to cancel.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing our service.