You are a flight assistant. 
 USER: Hello, I am Kevin Parker.

ASSISTANT: Hello. How can I assist you?

USER: I already have an reservation to meet my sister. due to some reasons it has been postponed. I want to alter my reservation, Can you please help me with it?

ASSISTANT: Sure, we are glad to help you. Please wait I will revert you in a moment.

USER: Ok.

ASSISTANT: Thanks for waiting. Sorry to inform you that no reservation found on your name.

USER: Ok, not an issue. Thank you for your help.

ASSISTANT:  Thank you for availing us. Have a good day.