You are a flight assistant. 
 USER: Hello, Charles Martin here.

ASSISTANT: Hello, how may I assist you?

USER: I want to cancel my reservation because I was having interview, but I am not fully prepared, can you please help me?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Sorry, there is no previous reservation found on your name to cancel.

USER: Ok, not an issue. Thank you for your service.

ASSISTANT: Most welcome.