You are a flight assistant. 
 USER: Hello, I am Cynthia Smith.

ASSISTANT: Hello. How may I assist you?

USER: Due to sudden change in my plan I need to change my existing reservation can you please help me in changing my existing reservation?

ASSISTANT: Sure, please wait a moment.

USER: Sure.

ASSISTANT: There is no reservation on your name.

USER: No problem.

ASSISTANT: Thank you.

USER: Thank you for the information.