怎么对多维数组的键名进行排序

如何对多维数组的键名进行排序
比如
$families = array
(
"Griffin"=>array
(
"Peter"=>50
),
"Brown"=>array
(
"Cleveland"=>30
)
);
正序排，排完序后的键名和对应的键值不变，形如下面的形式：
$families = array
(

"Brown"=>array
(
"Cleveland"=>30
)，
"Griffin"=>array
(
"Peter"=>50
)
);

------解决方案--------------------

PHP code

foreach($families as $v) 
      foreach($v as $vl) $p[]=$vl;
      
array_multisort($p,SORT_ASC,$families);      
print_r($families);