You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: I am Stephen Wright. 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: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Sorry to say, no reservation found with your name.

USER: No problem, thank you.

ASSISTANT: Thanks for reaching us.