You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I just want to change my recent reservation because my business trip postponed.

ASSISTANT: Can I know your name for documentation purpose?

USER: I am Margaret Allen.

ASSISTANT: Give me a moment.

USER: Sure.

ASSISTANT: Sorry, I didn't found any reservation basis on your details.

USER: It's ok, no issues. Thanks for your valuable information.

ASSISTANT: You are welcome.