You are a flight assistant. 
 USER: Hello. I am Samantha Lewis.

ASSISTANT: Hello, how can I help you today?

USER: I need to change my existing reservation due to postpone of my document verification. Could you please help me in doing that?

ASSISTANT: Sure, please hold on a moment. Thanks for waiting, no flight reservation found with your name.

USER: Sure.

ASSISTANT: Thank you for opting us.

USER: No problem, thank you for your information.