Fejlmelding ved brug af php i tællerscript

Hej,

Jeg kender stort set ikke noget til php, men har alligevel givet mig i kast med at sætte et tæller script op på min hjemmeside.
Som I nok kan regne ud er jeg røget ind i problemer.
Jeg får følgende fejlmelding:

Notice: Use of undefined constant month - assumed 'month' in D:\Websider\resadmin\hgc.dk\hgc.dk\www\test\index.php on line 40

Notice: Use of undefined constant mday - assumed 'mday' in D:\Websider\resadmin\hgc.dk\hgc.dk\www\test\index.php on line 41

Notice: Use of undefined constant year - assumed 'year' in D:\Websider\resadmin\hgc.dk\hgc.dk\www\test\index.php on line 42

Notice: Undefined variable: REMOTE_ADDR in D:\Websider\resadmin\hgc.dk\hgc.dk\www\test\index.php on line 47

På dette script:

    <?php
// Our log file;
$counter = "counter.txt";

// Date logging;
$today = getdate();
$month = $today[month];
$mday = $today[mday];
$year = $today[year];
$current_date = $mday . $month . $year;

// Log visit;
$fp = fopen($counter, "a");
$line = $REMOTE_ADDR . "|" . $mday . $month . $year . "\n";
$size = strlen($line);
fputs($fp, $line, $size);
fclose($fp);

// Read log file into array;
$contents = file($counter);

// Total hits;
$total_hits = sizeof($contents);

// Total hosts;
$total_hosts = array();
for ($i=0;$i<sizeof($contents);$i++) {
    $entry = explode("|", $contents[$i]);
    array_push($total_hosts, $entry[0]);
}
$total_hosts_size = sizeof(array_unique($total_hosts));

// Daily hits;
$daily_hits = array();
for ($i=0;$i<sizeof($contents);$i++) {
    $entry = explode("|", $contents[$i]);
    if ($current_date == chop($entry[1])) {
        array_push($daily_hits, $entry[0]);
    }
}
$daily_hits_size = sizeof($daily_hits);

// Daily hosts;
$daily_hosts = array();
for ($i=0;$i<sizeof($contents);$i++) {
    $entry = explode("|", $contents[$i]);
    if ($current_date == chop($entry[1])) {
        array_push($daily_hosts, $entry[0]);
    }
}
$daily_hosts_size = sizeof(array_unique($daily_hosts));

// Let's display everything;
echo "Total hits: " . $total_hits . "<br>Total hosts: " . $total_hosts_size . "<br>Daily hits: " . $daily_hits_size . "<br>Daily hosts: " . $daily_hosts_size;
?>