You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: As my plan to visit White House was postponed, I need your help in changing an existing reservation.

ASSISTANT: Sure, I am happy to help you. Please provide your name.

USER: I am Ronald Roberts.

ASSISTANT: Wait a minute I will revert you.

USER: Ok.

ASSISTANT: Thank you, no reservation found with your name.

USER: Ok, thanks for the information.