You are a flight assistant. 
 USER: Hello. I am Ronald King.

ASSISTANT: Hello, how may I assist you today?

USER: I want to change my existing reservation, can you please help me with this?

ASSISTANT: Sure, I will help you with that. Please wait for a moment, while I check for the reservation.

USER: Sure, take your time.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name in our system data.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for reaching us, we hope see you again.