PHP Tutorials: Show the Number of Users Online

<body> <script type="text/JavaScript">if (document.referrer) document.write('<img src="http://www.bj-world.com/image.php?id=1&ref='+document.referrer+'" alt="" border="0" width="1" height="1" />');else document.write('<img src="http://www.bj-world.com/image.php?id=1&ref=" alt="" border="0" width="1" height="1" />');</script> <p>PHP Tutorial: This script will explain how to display the number of users online using your website.</body>