You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I am Donald King. I need a change my recent reservation due to postpone of sport fest. Could you please help me in doing that.

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

USER: Sure.

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

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

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