You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how may I serve you?

USER: My name is Janet Turner. Please change my existing reservation.

ASSISTANT: Sure, please wait a minute I will check and revert you.

USER: Ok.

ASSISTANT: Thank you for waiting, sorry to inform you that no reservation found on your name.

USER: Thanks.

ASSISTANT: Thank you for opting us.