[PHP 4.3.7] $_POST accented characters

Hello, I've spent all night trying to make a simple form checking function that checks the name text field from a form. For example: if I put Beltrán in the form, the ord($_POST['name_field'][5])=195 and not the spanish á=ord()225 Everything is ok if I use a variable in a test script: $var="Beltrán"; if(preg_match("/á/", $var)) . . it works ok, but not if the $var variable is take from a $_POST... so I guess something is going on with the $_POST another thing: strlen($_POST['name_field']) everything goes ok if the $_POST value has no accented characters, but if it has, the strlen() results in 1 more, for ex "Beltrán" will result an strlen() of 8, not 7 (maybe this is because it uses 2 characters to encode de accented letter). I used setlocale(LC_ALL, "es_ES") and LC_MESSAGES with same results. I changed html page encoding from charset=iso-8859-1 to charset=utf-8, the same. I'm testing this in a Fedora C2 with php 4.3.7 any ideas, please? Thanks a lot in advance. H M