You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. May I know your good name please?

USER: My name is Karen Johnson.

ASSISTANT: OK Karen, how can I assist you?

USER: I want to change my reservation, can you please help me out.

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry for the inconvenience, there is no reservation found on your name.

USER: Its OK, no issues and thank you for your help.