function array_sort($arr,$keys,$type='asc') {
     $keysvalue = $new_array = array();
     foreach ($arr as $k => $v) {
     $keysvalue[$k] = $v[$keys];
     }
     if ($type == 'asc') {
       //对数组进行排序并保持索引关系
       asort($keysvalue);
     } else {
       //对数组进行逆向排序并保持索引关系
       arsort($keysvalue);
     }
     reset($keysvalue);
     foreach ($keysvalue as $k => $v) {
        $new_array[] = $arr[$k];
     }
     return $new_array;
}