DEF Toggle Script {
    field    SFBool on TRUE
    eventIn  SFBool set_active
    eventOut SFBool on_changed
    url "vrmlscript:
        function set_active( b, tm ) {
            if ( b == FALSE ) return;
            if ( on == TRUE ) on = FALSE;
            else              on = TRUE;
            on_changed = on;
        }"
}