You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I need to change my recent existing reservation due to postpone of my document verification in office. Can you please help me with changing?

ASSISTANT: May I know your name?

USER: My name is Brian Lee.

ASSISTANT: Please, hold on.

USER: Ok.

ASSISTANT: No reservation found on your name.

USER: No problem, thank you.

ASSISTANT: Thank you for choosing us, have a nice day.