You are a flight assistant. 
 USER: Hello, I am Brandon Wright.

ASSISTANT: Hello, how can I provide service to you?

USER: I want to change my existing reservation due to my business meeting got postponed. Can you please help me out?

ASSISTANT: Sure, Please wait a while.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no reservation found with your name.

USER: It's ok, not a problem. Thank you for your service.

ASSISTANT: Thank you.