You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you today?

USER: I am Brandon Edwards.

ASSISTANT: Ok.

USER: I want to change my existing reservation due to postpone of my friend engagement.

ASSISTANT: Sure, I will help you with that. Please wait, let me help you with checking the reservation.

USER: Sure.

ASSISTANT: Thanks for waiting. Sorry Brandon Edwards, there is no active reservation on your name to change it.

USER: Not an issue, thanks for your help.

ASSISTANT: Thanks for your presence.