You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I support you?

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

ASSISTANT: Sure, let me check the current status and revert you.

USER: Sure.

ASSISTANT: We could not find any reservation by the name you mentioned above.

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

ASSISTANT: Thank you for opting us.