You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I abet you?

USER: William White here. Due to inconvenience of my work, I want to change my reservation. Can you please help me for that?

ASSISTANT: Sure, I am here to help you. Please stand by.

USER: Thanks for that. I will wait.

ASSISTANT: Thanks for waiting.

USER: My pleasure.

ASSISTANT: I am sorry to say that there is no reservation found on William White.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for opting us.