[SOLVED] Decode Unicode String

I'm trying decode Unicode string pass via URL just like this website. I have trying and testing different functions found on Google but to no success  Only this website produce accurate results. Any ideas?

http://www.crypo.com/eng_urld.php

You'll have to give us more than that.  The string you're trying to decode and the Code you're using to decode the unicode. The results you're expecting. That's like saying. 

My car doesn't work. What's wrong with it?

The string can be anything based on what user input. As of now I'm testing with Thai characters but I think there is a function that decode Unicode character to their correct language (just like http://www.crypo.com/eng_urld.php <-- this is actually what I expect). The page uses UTF-8 as encoding. The result is the character corresponding to the Unicode. For Thai language the code table is http://www.unicode.org/charts/PDF/U0E00.pdf.

My test string is %u0E19%u0E32 which should output นา

<?php
header('Content-type: text/html; charset=utf-8');

function unicode2utf8($c)
{
    $output="";
   
    if($c < 0x80)
    {
        return chr($c);
    }
    else if($c < 0x800)
    {
        return chr( 0xc0 | ($c >> 6) ).chr( 0x80 | ($c & 0x3f) );
    }
    else if($c < 0x10000)
    {
        return chr( 0xe0 | ($c >> 12) ).chr( 0x80 | (($c >> 6) & 0x3f) ).chr( 0x80 | ($c & 0x3f) );
    }
    else if($c < 0x200000)
    {
        return chr(0xf0 | ($c >> 18)).chr(0x80 | (($c >> 12) & 0x3f)).chr(0x80 | (($c >> 6) & 0x3f)).chr(0x80 | ($c & 0x3f));
    }
    return false;
}

$string = '%u0E19%u0E32';

$string = preg_replace('#%u([0-9a-f]+)#ie', 'unicode2utf8(0x$1)', $string);

echo $string;

The unicode2utf8() function came from: http://php.net/manual/en/function.unicode-encode.php#79829

wowww .. thanks a lot, Daniel0! It works perfectly