You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you today?

USER: I am Nancy Green, I need to change my recent existing reservation due to postpone of my document verification in office.

ASSISTANT: Sure, we will help you. Please wait for a while, I will check the reservation list and inform you.

USER: Ok.

ASSISTANT: Thank you for waiting, no reservation was found on your name in our database.

USER: Fine, thanks for the information.

ASSISTANT: Thank you for availing us.