You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, good morning. I hope you are doing good today, how can I help you? We are from Central travel agency.

USER: Good morning, I need to make few changes in my existing reservation, because I have mentioned wrong dates previously.

ASSISTANT: Sure, let me know on which name did you booked the ticket?

USER: My name as per previous reservation was Stephen Young.

ASSISTANT: Ok, wait a while, let me check is there any previous reservation on your name.

USER: Sure, take your own time.

ASSISTANT: Stephen Young, sorry to say there is no reservation on your name.

USER: Oh! that's sad, maybe I have not booked my reservation properly.

ASSISTANT: I think so. Do you want to know anything else?

USER: No, thank you for your assistance.

ASSISTANT: You are welcome.