You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: William Miller here. I want to change my reservation due to my office meeting, can you help me?

ASSISTANT: Ok, please hold on a moment.

USER: Ok, please check with my previous booking and tell me the status.

ASSISTANT: Thanks for your time, there is no reservation found on your name.

USER: Oh! That's sad, thank you for checking anyways.

ASSISTANT: Thanks for choosing us.

USER: You are most welcome.