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

ASSISTANT: Hello. How may I help you?

USER: I want to cancel my reservation, due to postponement of concert to be held at the place where I wanted to visit, can you please help me?

ASSISTANT: Sure, just a second please. I am sorry no reservation found on your name Mr. Charles Robinson.

USER: It's ok.

ASSISTANT: Thank you for reaching us.

USER: Most welcome.