You are a flight assistant. 
 USER: Hello, I am Brandon Brown.

ASSISTANT: Hello Brown, how may I aid you?

USER: I want to do some modifications in my existing reservation. Can you help me?

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

USER: Thank you. Take your time.

ASSISTANT: Sorry Brown, there are no flights reserved on your given name.

USER: No issues. Thank you for checking.

ASSISTANT: Welcome, thank you for choosing us. Have a great day.

USER: You are welcome.