Anonymous

<html>
<head>
</head>
<body>
  <?php
	$size = "3";
	$submit = isset($_POST['command']);

	if(submit) {
		$size = $_POST['size'];
	
		if($size == "" || !ctype_digit($size) || $size > 12 || $size < 1) {print "size must be an integer between 1 and 12 (inclusive)"; }
		else {
			//page#2
			echo '<form action="<?php $_SERVER['PHP_SELF'] ?>" method="post">
	      		<input type="hidden" name="step" value="2" />
      	  	        <input type="hidden" name="size" value="3" />';
	  		echo '<select name="v0">';
			for($i=0; i < sizeof($size); ++$i) {
				echo '<option value="'.$i.'">unset</option>';
			}
			echo '</select>';	
			echo '<input type="submit" name="command" value="go"/><br />
	   	        </form>';
		}
	}
  
	//page#1

	echo '<form action="<?php $_SERVER['PHP_SELF'] ?>" method="post">
  	<input type="hidden" name="step" value="1" />
  	Size: <input type="text" name="size" value="'.$size.'" size="6" maxlength="40"/>&nbsp;
  	<input type="submit" name="command" value="go"/><br />
	</form>';

	//page#3	
	echo '<h1>And the answer is... 6</h1>';	
	
  ?>
</body>
</html>