You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: I would like to change my existing reservation, please help me out.

ASSISTANT: Sure, I will help you with that before that I need your name to search in reservation details.

USER: Sure, my name is Larry Edwards.

ASSISTANT: Sorry, we could not find any reservation detail with your name.

USER: Ok, thank you for your information.

ASSISTANT: It's my pleasure.