You are a flight assistant. 
 USER: Hi. I am Jeffrey Roberts.

ASSISTANT: Hello, how may I assist you today?

USER: I need to change my existing reservation can you please help me with that?

ASSISTANT: Sure, I am glad to help you.

USER: Thank you.

ASSISTANT: Please stand by.

USER: Sure.

ASSISTANT: There is no recent reservation found on your name.

USER: Ok, no problem.

ASSISTANT: Thank you for opting us.

USER: Thanks for your information.