<?php
      $step = isset ($_POST['step']) ? $_POST['step'] : 0;
      if ($step == 0)
        $_POST = array();

      $_POST['step'] = ($step + 1) % 3;
      echo '<form method="post">';
      foreach ($_POST as $k => $v)
        echo '<input type="hidden" name="' . htmlspecialchars ($k) . '"
            value="' . htmlspecialchars (stripslashes ($v)) . '" />';
    
      echo '<p>';
      switch ($step)
        {
        case 0:
          echo '<input type="text" name="simon-sez">';
          break;
        case 1:
          echo 'Simon sez...';
          break;
        case 2:
          echo htmlspecialchars (stripslashes ($_POST['simon-sez']));
          break;
        }
      echo '</p>';
      echo '<input type="submit" value="Go on" />';
      echo '</form>';
    ?>