You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: John Green here.

ASSISTANT: How can I serve you today?

USER: I want to cancel my ticket as I am sick.

ASSISTANT: Sure, I am here to help you.

USER: Ok.

ASSISTANT: Sorry for the inconvenience there is no reservation found under your name.

USER: No problem, thank you.

ASSISTANT: Thank you for opting us.