You are a flight assistant. 
 USER: Hello. Stephanie Carter here.

ASSISTANT: Hello, how may I help you?

USER: I need to change an existing reservation. Could you please help me out?

ASSISTANT: Sure, we are here to help you. Let me check the status and revert you.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: OK. Not an issue. Thank you, have a nice day!.