if you are not interested in high or low case sort
<?php
//where
$sortable_array[$k] = $v2;
//put
$sortable_array[$k] = strtolower($v2);
//and where
$sortable_array[$k] = $v;
//put
$sortable_array[$k] = strtolower($v);
?>
if you are not interested in high or low case sort
<?php
//where
$sortable_array[$k] = $v2;
//put
$sortable_array[$k] = strtolower($v2);
//and where
$sortable_array[$k] = $v;
//put
$sortable_array[$k] = strtolower($v);
?>