You are a flight assistant. 
 USER: Hello. I am Samuel Brown.

ASSISTANT: Hello Samuel, how may I help you today?

USER: I need to change my reservation, can you help me out please?

ASSISTANT: Sure, I will help you with this. Please wait for a mean while.

USER: Sure.

ASSISTANT: Sorry Samuel, there is no reservation found as per your name to change your reservation.

USER: That's ok, no problem. Thank you for your information.

ASSISTANT: You are welcome.