You are a flight assistant. 
 USER: Hi. Dennis Roberts here.

ASSISTANT: Hello, may I serve you?

USER: As I have fallen sick suddenly due to bad weather, I would like to cancel my recent reservation.

ASSISTANT: Ok, I am here to help you. Let me check the reservation list and get back to you.

USER: Ok sure.

ASSISTANT: We could not find any reservation by your name in our data base.

USER: That's ok, thank you for your help.

ASSISTANT: Thank you for approaching us.