You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am George Hernandez. Can you please help me to change my existing reservation?

ASSISTANT: Please wait for a while I will revert you back with the reservation status.

USER: Sure.

ASSISTANT: Sorry to inform you, there is no reservation found on your name to change it.

USER: Ok, no problem. Thank you for checking.

ASSISTANT: Thanks for choosing us, have a good day.