You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you today?

USER: I want to change my reservation due to postpone of my concert to be held at the place where I wanted to visit, can you please help me with it?

ASSISTANT: Sure, May I know your name please?

USER: I am Linda Jones.

ASSISTANT: Ok, Linda Jones, please hold on a minute.

USER: Ok'.

ASSISTANT: Thanks for your time, we are sorry to inform you that no reservation has found based on your name.

USER: Thanks for the information.

ASSISTANT: Thanks for choosing us.