You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, What can I do for you?

USER: I want to change my existing reservation as my exam got rescheduled. Please help me out.

ASSISTANT: Sure, May I know your name?

USER: I am Ronald White.

ASSISTANT: Please give a minute.

USER: Ok.

ASSISTANT: Sorry, No reservation found on your name. Thank you for availing us.

USER: Thank you for your response.