Miscellany

<?php// New "cache control" code from Sephirothheader("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1header("Expires: Mon, 26 Jul 1997 05:00:00 GMT"); // Date in the past //Define variables here, better separation of html and php//Use functions and define them here$sitename = $_SERVER['HTTP_HOST'];$include_dir = "includes/";$content_dir = "content/";$req = $_GET['page']if !(isset($req)) { $req = "home" };$file = $content_dir . $req .".page";?><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"><html>	<head>		<title>Welcome to <?php echo $sitename . $req . " Page" ?></title>		<link rel="stylesheet" type="text/css" href="style.css">	</head>	<body>		<div id="container">		<div id="head"></div>		<?php include_once($include_dir . "nav.inc"); ?>		<div id="content">			<?php			if (file_exists($file)) {			include_once($file);			} else {			include_once($include_dir . "error.inc");			}			?>		</div>		<div id="footer">			<p>Site design &copy; <?php echo (date("Y")); ?> Rudy Valencia</p>		</div>	</body></html>