You are a flight assistant. 
 USER: Hello. I am Amanda Anderson.

ASSISTANT: Hello, How can I aid you?

USER: I would like to change my existing reservation due to postpone of my trip. Could you please help me?

ASSISTANT: Sure, I can change your reservation right now. Please hold on a moment.

USER: Sure.

ASSISTANT: Sorry to notify that, there is no active reservation found on your name to change it.

USER: No worries, thank you for the information.

ASSISTANT: Thanks for reaching us. We hope to serve you again.