You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you?

USER: I want to change my reservation due to postponed of my exam, so please help me in changing.

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please provide your good name to proceed further.

USER: Sure, I am Jonathan Lewis.

ASSISTANT: Sorry, we did not find any active reservation on your name in our records.

USER: No worries, thank you.

ASSISTANT: Thank you for availing us.