Fix ugly badground on submenu

functions.php

@@ -129,7 +129,7 @@ function print_item($item, $class){
 
 function build_menu($parent, $tree){
     foreach($tree[$parent] as $i => $item){
-        $class=menu_active($item)?'active':'';
+        $class=menu_active($item)&&$parent==0?'active':'';
         if(array_key_exists($item->id, $tree)){
             echo '<li class="dropdown '.$class.'"><a class="dropdown-toggle" data-toggle="dropdown" href="#">'.menu_name($item).'<span class="caret"></span></a>';
             echo '<ul class="dropdown-menu">';