Chars

<!DOCTYPE htnk>
<html>
<head>
    <meta charset="utf-8">
</head>
<body>
<?php
mb_language('Neutral');
mb_internal_encoding('UTF-8');
mb_detect_order(array('UTF-8', 'ISO-8859-15', 'ISO-8859-1', 'ASCII'));

function mb_ord($string)
{
    if (extension_loaded('mbstring') === true)
    {
        $result = unpack('N', mb_convert_encoding($string, 'UCS-4BE', 'UTF-8'));
        if (is_array($result) === true)
        {
            return $result[1];
        }
    }
    return ord($string);
}
function onlyChars($string){
    $strlength = mb_strlen($string, 'UTF-8');
    $retString = "";
    for($i = 0; $i < $strlength; $i++){
        $char = ord($string[$i]);
        if(($char >= 48 && $char <= 57) ||
        ($char >= 65 && $char <= 90) ||
        ($char >= 97 && $char <= 122)){
            $retString .= $string[$i];
        }
        else
        {
            $retString .= '&#' . mb_ord(mb_substr($string, $i, 1, 'UTF-8')) . ';';
        }
    }
    return $retString;
}

$str = "Corné áßðóþúí azAZ109";
echo $str;
echo "<br/>\n";
echo onlyChars($str);
?>
</body>