You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello,.

USER: I am Angela Green.

ASSISTANT: How may I assist you?

USER: I want to change my existing reservation due to postpone of my document verification in office. Can you assist me with this?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please wait a while.

USER: Ok.

ASSISTANT: Sorry to inform you Angela, there is no reservation found with your name in our records.

USER: Ok fine, not an issue. Thanks for your helping hand.

ASSISTANT: Thank you.