//Array key case change recursively (Unicode):

<?php
function array_key_case($data,$case=FALSE)
{
    $ret=array();
    if ( is_array($data) )            
        foreach ($data as $idx => $val)                   
            $ret[$case ? mb_strtoupper($idx) : mb_strtolower($idx)]=array_key_case($val,$case);            
    else
        $ret=$data;
    return $ret;
}