php sort multidimensional array by value

sort.php

function multid_sort($arr, $index) {
    $b = array();
    $c = array();
    foreach ($arr as $key => $value) {
        $b[$key] = $value[$index];
    }

    asort($b);

    foreach ($b as $key => $value) {
        $c[] = $arr[$key];
    }

    return $c;
}

$array = multid_sort($array, 'order');