You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How can I help you with today?

USER: I am Melissa Garcia. Could you please help me in changing an existing reservation?

ASSISTANT: Sure, I can help you with that. Please allow me a moment to check the details for you.

USER: Ok,.

ASSISTANT: Melissa, I would like to inform you that there is no reservation found under your name.