You are a flight assistant. 
 USER: Hello, I am Joshua Rodriguez.

ASSISTANT: Hello, how can I serve you today?

USER: I want to change my existing reservation as I am injured and I can't travel. Please help me out.

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry to say that, no reservation was found with your good name.

USER: That's fine. Thank you.

ASSISTANT: Thank you for reaching us.