Conditional Statements, "isset" function and the "$_SERVER" PHP array

Today's Special

Source code:

<? require_once( 'site.php' ); ?>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html>
<head>
	<title> Today's Special 3 </title>
	<link rel="stylesheet" type="text/css" href="test.css" />
</head>
<body><div id="page">
	<div id="headder">
		<h1> Conditional Statements, "isset" function and the "$_SERVER" PHP array </h1>
	</div>

<div id="main-area">
		<?php
			/* if the "submit" variable does not exist, the form has not been submitted.
			Display this initial page. Othewise (the form has been submitted) jump
			to the else statement and display the result*/
			if (!isset($_GET['submit'])) 
				{
				?>
				<h2>Today's Special</h2>

<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="get">

<select name="day">
						<option value="1">Monday/Wednesday
						<option value="2">Tuesday/Thursday
						<option value="3">Friday/Sunday
						<option value="4">Saturday
					</select>
					<input type="submit" name="submit" value="Send">
				</form>

<?php
				}
			else
				{
				$day = $_GET['day'];
				switch ($day)
					{
					case 1:
						$special = 'Spaghetti';
						break;
					case 2:
						$special = 'Fish';
						break;
					case 3:
						$special = 'steak';
						break;
					default:
						$special = 'Mushroom Pie and Chips';
						break;
					}
				?>
				<h2>Today's Special is:</h2>

<?php
				echo $special;
				}
				?>
		</div>
        <div class="clearfloat">
        </div>
</div></body>
</html>