You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

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

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: Sure, I am Charles Collins.

ASSISTANT: Ok, please wait for a few minutes.

USER: Sure.

ASSISTANT: Thank you for your time, we did not find any active reservation on your name to change it.

USER: No issues, thank you.

ASSISTANT: Thank you for approaching us.