It is defined in the file ja_templatetools.php
function genMenuHead(){
global $ja_template_path,$ja_menutype, $ja_tool,$ja_font_size;
$html = "";
if ($ja_menutype == 1) {
$html = '<link href="'.$ja_template_path.'/ja_splitmenu/ja-splitmenu.css" rel="stylesheet" type="text/css" />';
}else if ($ja_menutype == 2) {
$html = '<link href="'.$ja_template_path.'/ja_cssmenu/ja-sosdmenu.css" rel="stylesheet" type="text/css" />';
} else if ($ja_menutype == 3) {
$html = '<link href="'. $ja_template_path .'/ja_transmenu/ja-transmenuh.css" rel="stylesheet" type="text/css" />
<script language="javascript" type="text/javascript" src="'.$ja_template_path.'/ja_transmenu/ja-transmenu.js"></script>';
} else if ($ja_menutype == 4) {
$html = '<link href="'.$ja_template_path.'/ja_cssmenu/ja-sosdmenu.css" rel="stylesheet" type="text/css" />
<script language="javascript" type="text/javascript" src="'. $ja_template_path.'/ja_cssmenu/ja.cssmenu.js"></script>';
}
This is not joomla code but template related.