You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you today?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Sure, I am here to help you out. Please provide me your name to check the reservation status.

USER: Joseph Nelson here.

ASSISTANT: Please allow me a moment.

USER: Ok.

ASSISTANT: Sorry Joseph Nelson, there is no flight reservation on your name in our database.

USER: No issues, thank you.

ASSISTANT: Thank you for reaching us Joseph Nelson.