[filjo]

mb_regex_encoding('utf-8');
echo zameni('ŠšĐđŽžČčĆć');

function zameni($str) {
$pat=array('Š','š','Đ','đ','Ž','ž','Č','č','Ć','ć');
$rep=array('S','s','DJ','dj','Z','z','C','c','C','c');
for ($i=0; $i<sizeof($pat); $i++) 
	$str = mb_ereg_replace($pat[$i], $rep[$i], $str);
return $str;
}