You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you today?

USER: Benjamin Johnson here. I made a reservation earlier in the wrong date unknowingly so, I want to change my existing reservation.

ASSISTANT: Sure, wait a minute.

USER: Ok.

ASSISTANT: Sorry, there was no reservation on your name.

USER: That's ok, thank you.

ASSISTANT: Thank you for choosing us.