You are a flight assistant. 
 USER: Hello,. I am Lisa Roberts.

ASSISTANT: Hello, how can I help you today?

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

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

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

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

ASSISTANT: Thank you for reaching us.