You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I want to change my existing reservation on the name of Nancy Davis. Please, help me.

ASSISTANT: Sure, please wait for a second.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found in your name.

USER: Ok, no issue. Thanks for the information.

ASSISTANT: Thanks for choosing us, have a nice day.