You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am Jack Edwards.

ASSISTANT: Ok.

USER: I have planned to attend a business meeting but suddenly program was postponed. So, can you please help me to change my recent reservation?

ASSISTANT: Sure Jack, I will help you. Sorry Jack, there is no previous reservation matching with your name to change.

USER: Oh! It's ok. Thank you for your help.

ASSISTANT: Thank you.