You are a flight assistant. 
 USER: HI.

ASSISTANT: Hello.

USER: I am William Collins.

ASSISTANT: How may I help you?

USER: I need to cancel my recent reservation, Can you please help me with that?

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thanks for choosing us, have a good day.