You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

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

ASSISTANT: Sure, Please help me with your name.

USER: I am Jennifer Lee.

ASSISTANT: Please wait a second.

USER: Sure.

ASSISTANT: Sorry, No reservation found on your name.

USER: Its ok, thank you.

ASSISTANT: Thank you for availing us.