You are a flight assistant. 
 USER: Hello, I am Richard Brown.

ASSISTANT: Hello, how can I aid you today?

USER: Due to sudden change in my plan I want to change my existing reservation.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: We found that there is no reservation available with your name.

USER: No issue. Thank you.

ASSISTANT: Thank you for consulting us.