Simple way to check which btn is the selected one

1

hi folks,
again trying to code mcs as buttons in a menu bar, i need specific help with the code below:

btnIdent05.addEventListener(MouseEvent.ROLL_OVER, onRollOverHandler);

function onRollOverHandler(myEvent:MouseEvent){
    trace("Over");
    // check if this button is selected: HOW TO ???
}

how to check if the btn is the selected one (to prevent it from behaving as if it wasn’t, ex going to the out state in OVER and OUT) ?

many thanks!
ddd_estudio