二次元連想配列を並べ替える

function ary_orderby (&$ary_param, $str_orderby, $bol_desc=False) {

	if (strlen($str_orderby) === 0) {

		return False;

	}
	$ary_sortkey = array();

	foreach ($ary_param as $idx_1 => $val_1){

		$ary_sortkey[$idx_1] = $val_1[$str_orderby];

		unset($idx_1);

		unset($val_1);

	}
	if ($bol_desc === False) {

		array_multisort($ary_sortkey, SORT_ASC, $ary_param);

	} else {

		array_multisort($ary_sortkey, SORT_DESC, $ary_param);

	}

	unset($ary_sortkey);

}