You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you today?

USER: I want to change my existing reservation, due to postpone of my examination. Can you help me out?

ASSISTANT: Sure, I am always here to help you. Can you please provide your name?

USER: Myself Larry Taylor.

ASSISTANT: Please, wait.

USER: Sure.

ASSISTANT: Thanks for your time, there is no active reservation found on your name.

USER: Ok, not an issue. Thank you for your valuable information.

ASSISTANT: Thank you for availing us.