Forums Scripts & Popups trying to use on:usermode

Can someone explain how to use this properly. I have tried as the help file explains, but it does not seem to trigger when any usermodes are changed.

EDIT: Actually, this may not be what I want. I am trying to find out which event I need to use when I get set +o or other op modes. These seem to not be on:mode or on:usermode, so any help would be appreciated