Errore contatore

[bgp]

dov'è l'errore in questo contatore con cookies?Io non riesco a trovarlo...

$c_ip = $HTTP_COOKIE_VARS["user_ip"]; 
$counter_file = "counter/count.txt"; 
$counter_file_line = file($counter_file);  if(!$c_ip) { 
setcookie("user_ip", $REMOTE_ADDR, time()+360000);  $counter_file_line[0]++; 
$cf = fopen($counter_file, "w+"); 
fputs($cf, "$counter_file_line[0]");     fclose($cf); 
} 
elseif($c_ip != $REMOTE_ADDR){ 
$counter_file_line[0]++;   $cf = fopen($counter_file, "w+"); 
fputs($cf, "$counter_file_line[0]"); 
fclose($cf); 
} 

mi da errore alla riga 1:
Undefined index: user_ip

e alla riga 4:
Undefined variable: REMOTE_ADDR