You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER: I want to change my reservation due to postponed of my semester exam, so please help me in changing.

ASSISTANT: Sure, Please wait a second.

USER: Sure, please check my reservation on the name of Donald Jones.

ASSISTANT: Sorry, No reservation found on your name.

USER: No issues, thank you.

ASSISTANT: Thank you for availing us.