You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. What can I do for you?

USER: I would like to change my existing reservation which I have done last night. So, can you help with it?

ASSISTANT: Sure, I will help you. Please wait a moment. May I know your name for checking your reservation?

USER: My name is Janet Davis.

ASSISTANT: No reservation found on your name Janet Davis. You want to know anything else from us?

USER: No, I don't want any thing right now. Thank you for the information.