in the webassist/plugins/side_menu/nested_accoridon/sidemenu.php file, change:
<script type="text/javascript" src="functions.js"></script>
to:
<script type="text/javascript" src="../accordion/js/accordion.js"></script>
<script type="text/javascript" src="functions.js"></script>
if you still have problems, send a link where i can see your page.