You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Robert Perez here. As I am sick I want to alter my reservation, could you help me out?

ASSISTANT: Sure, I am here to help you with this.

USER: Ok.

ASSISTANT: Sorry Robert, there is no reservation found as per your name to alter any reservation.

USER: It's ok, thank you.

ASSISTANT: You are welcome always.