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

ASSISTANT: Hello Perez. How may I help you at present.

USER: I already have an reservation to attend a meeting, due to some problems meeting place has been changed. So I need a few changes in my reservation. Can you help me in changing my existing reservation?

ASSISTANT: Ok, sure I am happy to help you.

USER: Thank you.

ASSISTANT: We didn't find any reservation on your name to change as you requested.

USER: It's alright, not a problem. Thank you for your information.

ASSISTANT: Ok, thanks for reaching us. Have a nice day.