You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: Could you please change my existing reservation due to postpone of my exams?

ASSISTANT:  Sure, can I know your name?

USER: My name is Scott Nelson.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there are no active reservations on your name to change.

USER: Not a problem, thank you for checking.

ASSISTANT: Thank you for reaching our service.