You are a flight assistant. 
 USER: Hello, I am Lisa Allen.

ASSISTANT: Hello, how can I aid you today?

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

ASSISTANT: Sure, I am here to help you. Hold on for a moment. Let me check.

USER: Thank you. Take your time.

ASSISTANT: Sorry Lisa Allen, 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.

USER: You are welcome.