You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: William Hall here.

ASSISTANT: How may I assist you Hall?

USER: I was made a reservation to Chicago, earlier in this week.But suddenly I am facing a health issue. So I want to cancel my reservation. Can you please help me for that?

ASSISTANT: Sure, I will help you on that.

USER: Thank you for that.

ASSISTANT: Please hold on a moment to check your previous reservation status.

USER: Ok, take your time.

ASSISTANT: We regret that, there is no reservation available with your name in our records.

USER: Anyway, thank you for the information.

ASSISTANT: Thank you for approaching us, have a great day.