Hjälp med mitt gymnasiearbete, meny från databas (bootstrap)

<?php
$result = mysql_query("SELECT * FROM toppmeny");
while($row = mysql_fetch_assoc($result)) {
	$menu_items = array(
		array('id'=>$row["id"], 'link'=>$row["link"], 'name'=>$row["title"], 'parent_menu_id'=>$row["parent_id"])
	);
	// print_r($menu_items);
}
global $menuItems;
global $parentMenuIds;
//create an array of parent_menu_ids to search through and find out if the current items have an children
foreach($menu_items as $parentId)
{
  $parentMenuIds[] = $parentId['parent_menu_id'];
}
//assign the menu items to the global array to use in the function
$menuItems = $menu_items;

//recursive function that prints categories as a nested html unorderd list
function generate_menu($parent)
{
		$has_childs = false;

		//this prevents printing 'ul' if we don't have subcategories for this category
		global $menuItems;
		global $parentMenuIds;
		//use global array variable instead of a local variable to lower stack memory requierment
		foreach($menuItems as $menuItem)
		{
			if ($menuItem['parent_menu_id'] == $parent)
			{
				//if this is the first child print '<ul>'
				if ($has_childs === false)
				{
				  //don't print '<ul>' multiple times
				  $has_childs = true;
				  if($parent != 0)
				  {
					echo '<ul class="dropdown-menu">';
				  }
				}
				if($menuItem['parent_menu_id'] == 0 && in_array($menuItem['id'], $parentMenuIds))
				{
				  echo '<li class="dropdown"><a class="dropdown-toggle" data-toggle="dropdown" href="#">' . $menuItem['name'] . '<b class="caret"></b></a>';
				}
				else if($menuItem['parent_menu_id'] != 0 && in_array($menuItem['id'], $parentMenuIds))
				{
				  echo '<li class="dropdown-submenu"><a href="'. $menuItem['link'] .'">' . $menuItem['name'] . '</a>';
				}
				else
				{
				  echo '<li><a href="'. $menuItem['link'] .'">' . $menuItem['name'] . '</a>';
				}
				generate_menu($menuItem['id']);

				//call function again to generate nested list for subcategories belonging to this category
				echo '</li>';
			}
		}
		if ($has_childs === true) echo '</ul>';
}
generate_menu(0);
?>

$menu_items = array(
array('id'=>$row["id"], 'link'=>$row["link"], 'name'=>$row["title"], 'parent_menu_id'=>$row["parent_id"])
);

Array ( [0] => Array ( [id] => 1 [link] => index.php [name] => Start [parent_menu_id] => 0 ) )