You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I want to cancel my reservation, due to some health problems I am unable to travel those dates, can you please cancel my reservation?

ASSISTANT: Sure, I will help you with that.

USER: Thanks.

ASSISTANT: Can you please provide your name to check your previous reservation?

USER: Sure, my name is David Miller.

ASSISTANT: Sorry to inform you that, there is no reservation found with your name in our records.

USER: Oh! It's ok no problem. Thank you for your information.

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