You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am William Davis.

ASSISTANT: How may I assist you?

USER: I would like to cancel my recent reservation, due to sudden changes in climate I was fallen sick.

ASSISTANT: Sure, I will help you.

USER: Could you please help me in cancellation?

ASSISTANT: Please wait a moment, I will check the reservation list.

USER: Sure.

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

USER: Ok, no worries at all. Thank you.

ASSISTANT: Thank you.