You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I want to change my reservation, due to postponement of concert to be held at the place where I wanted to visit, can you please take your precious time for helping me?

ASSISTANT: Sure, may I know your name?

USER: I am Joseph Young.

ASSISTANT: Sorry Young, no reservation found on your name.

USER: Oh! ok that's fine. Any way thank you for the information.

ASSISTANT: Thank you for reaching us. Welcome.