PHP Tutorials: Site Up Down Script

<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: Check if a remote website is up or down with this handy script</body>