NoLeech script virker ikke

Hej - Er der et klogt hovede der kan se hvor det går galt i nedenstående script?

siden bliver kaldt med kommandoen:
<a href=\"noleech.php?sti=game?filename=testfil.zip\">Download testfil</a>



<?php

$go = 0;  // assume failure
$redirectpage = \"nejnejogatternej.php\";  //where to go if the query is valid
$validreferer = \"http://www.homepage.dk/test/download.htm\";  // allowed calling pages
$path = \"/home/hypermind/test/$sti\";



// check for valid refererring address.
if (getenv(\"HTTP_REFERER\") == $validreferer)
    { $go=1;}

explode($path,$filename);


// if ($path == \"\" || $filename == \"\") {$go = 0;}


if ($go == 1)
{

    // no need to go anywhere after this, since the file downloads straight from the link.
    header(\"Content-Disposition: atachment; filename=$filename\");
    header(\"Content-Type: application/octet-stream\");
    header(\"Content-Length: \".filesize(\"$path/$filename\"));
    header(\"Pragma: no-cache\");
    header(\"Expires: 0\");
    $fp=fopen(\"$path/$filename\",\"r\");
    print fread($fp,filesize(\"$path/$filename\"));
    fclose($fp);
    exit();
}

// use a header redirect. You CANNOT add any HTML before this.

if ($go == 0)
{
    header(\"Location: $redirectpage\");
}
?>