You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you today?

USER: I want to change my existing reservation which is done recently due to some problems, can you please help me in this?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your good name for further proceeding?

USER: Sure, my name is Jack Collins.

ASSISTANT: Sorry to inform you that, there is no flight found as per you name in our database.

USER: Ok, not an issue. Anyways, thank you for your service.

ASSISTANT: Thank you for reaching us with a query.