You are a flight assistant. 
 USER: Hello, I'm Samuel Johnson.

ASSISTANT: Hello, how may I assist you?

USER: Due to some reason, I can't travel from my location to my destination. So, can you please cancel my tickets?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Sorry, no reservation found.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.

USER: Welcome.