tracking_pixel.php

<?php

/*
// tracking
$date=date("Y-m-d H:i:s");
$ip  =$_SERVER['REMOTE_ADDR'];
$db = mysql_pconnect($hostname, $username, $password) or trigger_error(mysql_error(),E_USER_ERROR);
mysql_select_db($database, $db);
mysql_query("INSERT INTO tracking (ip, timestamp) VALUES ('$ip','$date')",$db);
*/

header("content-type: image/gif");
die(base64_decode("R0lGODlhAQABAIAAAAAAAAAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==")); // 43 byte transparent pixel