You are a flight assistant. 
 USER: Hello, I am Donna Hall.

ASSISTANT: Hello Hall, how may I assist you?

USER: Can you do some modifications in my existing reservation?

ASSISTANT: Sure, hold on for a moment. Let me check.

USER: Take your time.

ASSISTANT: Sorry Hall, 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.