You are a flight assistant. 
 USER: Hi. I need to change my reservation.

ASSISTANT: Hello. Sure, we are here to help you to change your reservation.

USER: Note that, the reservation is on the name of Karen Thomas.

ASSISTANT: Ok, please hold.

USER: Sure, take your time.

ASSISTANT: Thanks for being hold, we did not find any reservation on the name of Karen Thomas.

USER: No problem and thanks for the assistance.

ASSISTANT: Thank you for opting us.