You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I would like to change my existing reservation, which is done recently. Can you please help me out?

ASSISTANT: Sure, I am here to help you with that, may I know your name to proceed further?

USER: Thank you for considering my request. Myself Dennis Martin.

ASSISTANT: Sorry to inform you that there is no active reservation on your given name.

USER: Not an issue, anyway thank you for the information.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your service.