You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: I want to postpone my trip due to an emergency. Can you aid me in amending my existing reservation?

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: It was reserved on the name Matthew Harris.

ASSISTANT: Sorry Matthew Harris, there are no flights reserved on your given name formerly.

USER: No issues. Thank you for checking.

ASSISTANT: Welcome, thank you for choosing us. Have a safe flight.