You are a flight assistant. 
 USER: Hello, I am Andrew Robinson.

ASSISTANT: Hello, how may I assist you?

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

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

USER: Take your time.

ASSISTANT: Sorry Robinson, there are no flights reserved on your name. Welcome, thank you for choosing us.

USER: No issues. Thank you for checking.