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

ASSISTANT: Hello, how may I assist you?

USER: Owing to an emergency, I want to cancel my reservation. Please help me in cancellation.

ASSISTANT: Sure, please wait a minute I will check and revert to you.

USER: Ok.

ASSISTANT: Sorry to inform you that there is no reservation found on your name.

USER: Ok, no issues.

ASSISTANT: Thank you for choosing us.

USER: Thank you for your response.