如何用perl cgi upload一個文件到server？

我從一個網站看到以下的source code：
#!/usr/bin/perl -w

use CGI;

$upload_dir = "/home/mywebsite/htdocs/upload";

$query = new CGI;

$filename = $query->param("photo");
$email_address = $query->param("email_address");
$filename =~ s/.*[\/\\](.*)/$1/;
$upload_filehandle = $query->upload("photo");

open UPLOADFILE, ">$upload_dir/$filename";

binmode UPLOADFILE;

while ( <$upload_filehandle> )
{
   print UPLOADFILE;
}

close UPLOADFILE;

但是為什麼我還是無發成功upload文件？