PHP function code to determine character set and transcode

function safeEncoding($string,$outEncoding ='UTF-8')
{
 $encoding = "UTF-8";
 for($i=0;$i {
 if(ord($string{$i})<128)
 continue;

 if((ord($string{$i})&224)==224)
 {
 //The first byte passed the judgment
 $char = $string{++$i};
 if((ord($char)&128)==128)
 {
 //The second byte passed the judgment
 $char = $string{++$i};
 if((ord($char)&128)==128)
 {
 $encoding = "UTF-8";
 break;
 }
 }
 }

 if((ord($string{$i})&192)==192)
 {
 //The first byte is judged through
 $char = $string{++$i};
 if((ord( $char)&128)==128)
 {
 // The second byte is judged through
 $encoding = "GB2312";
 break;
 }
 }
 }

 if(strtoupper($encoding) == strtoupper ($outEncoding))
 return $string;
 else
 return iconv($encoding,$outEncoding,$string);
}
?>