You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation due to some issues, can you please help me with that?

ASSISTANT: Ok, I will help you, please provide me your name.

USER: Sure, I am William Green.

ASSISTANT: Ok, Please wait.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no active reservation on your name.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you.