$book->focus( $book->raised );
$book->focusFollowsMouse;

##</code><code>##

$mw->focusFollowsMouse;

##</code><code>##

$book->bind(  '<Control-Tab>',  \&RaiseNext );
$book->bind(  '<Shift-Control-Tab>', \&RaisePrev );
sub RaiseNext {
    my( $nb ) = @_; 
    $nb->raise( $nb->info("focusnext") );
}
sub RaisePrev {
    my( $nb ) = @_; 
    $nb->raise( $nb->info("focusprev") );
}