You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you today?

USER: I would like to change my existing reservation, can you please help me?

ASSISTANT: Sure, I am happy to help you in changing. Please, share me your good name to check your reservation status.

USER: Stephanie Perez.

ASSISTANT: Ok, please wait for a minute.

USER: Sure.

ASSISTANT: We are sorry to inform you that, we have not found any active reservation on your name in our records.

USER: Ok, not a problem. Thank you.

ASSISTANT: Thank you for opting us.