Joomla default menu (homepage), view, option variables in index.php
// if a section set background body type for background image
$menu = &JSite::getMenu();
// echo the menu item name
echo $menu->getActive()->name;
echo $menu->getActive()->id; // id number
if ( JRequest::getCmd('view') === "section" ) {
// connect to database
]$db = &JFactory::getDBO();
$temp = JRequest::getString('id');
$temp = explode(':', $temp);
$id = $temp[0];
$db->setQuery('SELECT title FROM #__sections WHERE id='.$id);
$sname=$db->loadResult();
$sname=str_replace(" ","_",$sname);
$sname=str_replace("'","",$sname);
echo "_".strtolower($sname);
}
elseif ( ($menu->getActive() == $menu->getDefault()) || ( JRequest::getCmd('view') === "frontpage" ) ) {
echo "_homepage";
}