Upload php mysql (mp3 y buscador)

[newnovato]

creo que el problema lo tengo aqui

{
header('Location: 404.php');
}
function bytes2English($filesize)
{

if ($filesize<1048676)
RETURN number_format($filesize/1024,1) . " KB";
if ($filesize>=1048576 && $filesize<1073741824)
RETURN number_format($filesize/1048576,1) . " MB";
if ($filesize>=1073741824 && $filesize<1099511627776)
RETURN number_format($filesize/1073741824,2) . " GB";
if ($filesize>=1099511627776)
RETURN number_format($filesize/1099511627776,2) . " TB";
if ($filesize>=1125899906842624) //Currently, PB won't show due to PHP limitations
RETURN number_format($filesize/1125899906842624,3) . " PB";
}