You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: My name is Patrick Wilson.

ASSISTANT: Glad to meet you Wilson.

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

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

USER: Sure, take your time.

ASSISTANT: Sorry Wilson, there are no flights reserved on your name formerly.

USER: That's ok, thank you for checking.

ASSISTANT: Welcome, thank you for choosing us.

USER: Welcome.