You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you for the day?

USER: I am Debra Lewis. Can you please help me in changing my existing reservation, as my exam got postponed.

ASSISTANT: Sure, I am mirthful to help you with this.

USER: Thank you.

ASSISTANT: Please allow me a moment, let me check your previous reservation status. I am really sorry to inform you that there is no active reservation found on your name to change it.

USER: Ok. Ok, no issues. Thank you for your help.

ASSISTANT: Thank you for reaching us, have a great day.