Thank you very much for this great book! The only trouble I have is displaying CSS in chapter 18. No one php script in chapter 18 does display CSS style, except for index.html, it displays CSS like in examples in the book. I cannot understand why. For example, below is a source code generated from Script 18.5 - index.php, it does includes CSS style reference but doesn't display it in a browser.
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Welcome to this Site!</title>
<link rel="includes/layout.css">
</head>
<body>
<div id="Header">User Registration</div>
<div id="Content">
<!-- End of Header --><h1>Welcome, roman!</h1><p>Spam spam spam spam spam spam
spam spam spam spam spam spam
spam spam spam spam spam spam
spam spam spam spam spam spam.</p>
<p>Spam spam spam spam spam spam
spam spam spam spam spam spam
spam spam spam spam spam spam
spam spam spam spam spam spam.</p>
<!-- Start of Footer -->
</div><!-- Content -->
<div id="Menu">
<a href="index.php" title="Home Page">Home</a><br>
<a href="logout.php" title="Logout">Logout</a><br>
<a href="change_password.php" title="Change Your Password">Change Password</a><br>
<a href="#">Some Page</a><br>
<a href="#">Another Page</a><br>
</div><!-- Menu -->
</body>
</html>
