You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I render you today?

USER: I want to amend my existing reservation. Can you aid me in doing some changes in my existing reservation?

ASSISTANT: Sure, I am here to help you. May I know on whose name the ticket has been reserved formerly?

USER: Take your time. I am Samantha Lewis.

ASSISTANT: Sorry Samantha Lewis, 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 great day.