Valideringskod
      *   *****   *******  *******   *****   
      *  *     *     *        *     *     *  
      *        *     *        *     *        
      *       *      *        *     *        
      *     **       *        *     *   ***  
*     *   **         *        *     *     *  
 *****   *******     *        *      *****