Hello Tom, thanks for your info. Tom would like to ask how can I do to use logoff menu to link to other pages remaining in same browser tab.

The links are created in web/staff/include/tpl.body.header.inc.php line 32

<a class="dmenu_item" href="<?php echo $hm->Url( '_sc=' . $sc . '&' ); ?>"
><?php echo $caption; ?></a>

Maybe you should entirely replace it with your own code instead of modifying it because the original code is not designed to have a static url.