You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: Please change my active reservation as my meeting was changed.

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know on whose name the ticket has been reserved formerly?

USER: Justin Lopez.

ASSISTANT: Sorry Justin Lopez, there are no flights reserved on your given name formerly.

USER: Ok, no problem. Thank you.

ASSISTANT: Welcome, thank you for choosing us. Have a great day.