请问如何把汉字转化成unicode码？？谢谢

比如，把：“最新推荐GB”转化成：

最新推荐GB

请问算法。谢谢
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测试成功，gb2312.txt下载
http://www.phpx.com/download/utf8/gb2312.txt

function gb2utf8($gb)
{
if(!trim($gb))return $gb;
$filename="gb2312.txt";
$tmp=file($filename);
$codetable=array();
while(list($key,$value)=each($tmp))
$codetable[hexdec(substr($value,0,6))]=substr($value,7,6);

$utf8="";
while($gb)
{
if (ord(substr($gb,0,1))>127)
{
$this=substr($gb,0,2);
$gb=substr($gb,2,strlen($gb));
$utf8.="&#x".dechex(hexdec($codetable[hexdec(bin2hex($this))-0x8080])).";";
}
else
{
$utf8.="&#x".dechex(ord(substr($gb,0,1))).";";
$gb=substr($gb,1,strlen($gb));
}
}

return $utf8;
}

echo gb2utf8("中文Abc");