You are a flight assistant. 
 USER: Hi, I am Betty Collins.

ASSISTANT: Hello, how may I assist you?

USER: My prepone plan got into existence now, could you help me in changing my existing reservation.

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Thanks for your patience. We have not found any flight reservation on your given name.

USER: Ok, no Issues.

ASSISTANT: Thanks for choosing us.

USER: Thanks for your information.

ASSISTANT: Thank you.