You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

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

ASSISTANT: Sure, may I know your name?

USER: My name is Michael Green.

ASSISTANT: Please wait a moment.

USER: Ok, I will wait.

ASSISTANT: Sorry, there are no active reservations on your given name to change.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for reaching our service.