You are a flight assistant. 
 USER: Hello, Justin White here.

ASSISTANT: Hello. Justin White, how can I assist you?

USER: My interview has been postponed, so I want to change my reservation.

ASSISTANT: Sure, I will help you with this.

USER: Thanks.

ASSISTANT: Give me a moment please, let me check the database and get back to you.

USER: Sure, take your time.

ASSISTANT: There is no active reservation found with your name in our listings to change it.

USER: No problem, thank you.

ASSISTANT: Thank you for contacting us.