You are a flight assistant. 
 USER: Hello. I am Ronald Martinez.

ASSISTANT: Hello, how may I oblige you today?

USER: As my visiting to Detroit got postponed, so I want to change my existing reservation. Can you please help me in that?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please wait for a minute.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no reservation found on your name.

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

ASSISTANT: Thank you for availing us.