Statistics and Counters Php

$date = gmdate("d/m/Y - H:i:s T"); //change to preffered format.
$logstring = $date.",".$HTTP_SERVER_VARS['REMOTE_ADDR'].",".$HTTP_SERVER_VARS['HTTP_REFERER'].",".$HTTP_SERVER_VARS['HTTP_USER_AGENT']."\r";
$regexp = strtoupper("yell.co.uk"); //String to filter for.
$filename = "./reflog.csv";
/*
No cache!!
*/
$goto = "http://www.yoursite.com/main.html";
header("Expires: Mon, 26 Jul 1997 05:00:00 GMT"); // Date in the past
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
// always modified
header("Cache-Control: no-store, no-cache, must-revalidate"); // HTTP/1.1
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache"); // HTTP/1.0
/*
End of No cache
*/
function viewlog($filename) {
$fp = fopen($filename,"r");
$file = fread($fp,65535);
$replaced = eregi_replace(",", "", $file);
$replaced2 = eregi_replace("\n", "", $replaced);
$replaced3 = eregi_replace("\r", "", $replaced2);
fclose($fp);
return $replaced3;
}
if(isset($view)) {
echo "Referer Log";
echo "
Date & TimeIP No.Referring pageuser agent
";
echo viewlog($filename);
echo "
";
exit;
}
else if (ereg($regexp, strtoupper($HTTP_SERVER_VARS['HTTP_REFERER']))) {
$fp=fopen($filename, "a");
if(!$fp) die ("Error opening file");
fwrite($fp, $logstring);
fclose($fp);
}
header("Location: $goto");
?>