Untitled

<?php session_start(); ?>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "DTD/xhtml1-transitional.dtd">
<html>
<head>
   <title>Captcha demo</title>
</head>
<body>
<?php
   if (isset($_POST['submitBtn'])){
      $secCode = isset($_POST['secCode']) ? strtolower($_POST['secCode']) : "";
      if ($secCode == $_SESSION['securityCode']) {
         echo "<p>The result code was valid!<br/></p>";
         unset($_SESSION['securityCode']);
         $result = true;
      }
      else {
         echo "<p>Sorry the security code is invalid! Please try it again!</p>";
         $result = false;
      }
   }

   if ((!isset($_POST['submitBtn'])) || (!$result)){
?>
      <form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post" >
        <table width="400">
          <tr>
            <td>Security code:
               <input class="text" name="secCode" type="text" size="10" />
            </td>
            <td>
               <img src="securityCode.php" alt="security code" border="1" />
            </td>
          </tr>
          <tr>
            <td colspan="2" align="center"><br/>
               <input class="text" type="submit" name="submitBtn" value="Send" />
            </td>
          </tr>
        </table>
      </form>
<?php
   }
?>
</body>