<?
$server = '';
$user = '';
$pass = '';
$db2 = '';

$db = mysql_connect($server, $user, $pass) or die("Could not connect.");
if(!$db)
    die("no db");
if(!mysql_select_db("$db2",$db))
    die("No database selected.");
$server_time=date("U");
$client_ip=$_SERVER['REMOTE_ADDR'];

$query = mysql_query("SELECT * FROM current_users WHERE ip='$client_ip'");
$check = mysql_fetch_array($query);
if($check) {
    $update="UPDATE current_users set time='$server_time' where ip='$check[ip]'";
    mysql_query($update) or die("Unable to process update: " . mysql_error());
} else {
  $sql = "INSERT INTO `current_users` (`ip`, `time`) VALUES ('$client_ip', '$server_time')";
  $result = mysql_query($sql) or die("Unable to process insert: " . mysql_error());
}
$time=$server_time-600;
$remove = "DELETE from current_users WHERE time<'$time'"; // Remove users outside time limit
mysql_query($remove) or die("Unable to delete: " . mysql_error());

// Show the count
$sql2 = mysql_query("SELECT ip FROM current_users" );
$currentVisitors = mysql_num_rows($sql2);
echo $currentVisitors;
?>