You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I want to change my existing reservation as I have postponed my meeting.

ASSISTANT: Sure, may I know your name?

USER: My name is Dorothy Rodriguez.

ASSISTANT: Ok, please wait a moment.

USER: OK.

ASSISTANT: Sorry, there is no reservation found based on your details.

USER: Ok, no problem. Leave it. Thanks for the information.

ASSISTANT: Thank you.