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

ASSISTANT: Hello, how can I aid you today?

USER: I would like to cancel my reservation due to sudden plan change in the trip, can you help me in cancellation?

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

USER: Ok.

ASSISTANT: Thank you for being wait. Unfortunately there is no reservation found by your name.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for being with us.