array_merge_recursive_distinct

  function &array_merge_recursive_distinct(array &$array1, &$array2 = null)
	{
	  $merged = $array1;
	 
	  if (is_array($array2))
	    foreach ($array2 as $key => $val)
	      if (is_array($array2[$key]))
		$merged[$key] = is_array($merged[$key]) ? array_merge_recursive_distinct($merged[$key], $array2[$key]) : $array2[$key];
	      else
		$merged[$key] = $val;
	 
	  return $merged;
	}