You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: My name is Paul Lewis, I want to change my existing reservation due to postpone of my client meeting.

ASSISTANT: Sure, please give me a minute.

USER: Ok.

ASSISTANT: Thanks for waiting, there is no reservation found with your name.

USER: No problem, thank you.

ASSISTANT: Thank you.