Hola,
Al ejecutar add.php:
Cita: Not Found
The requested URL /ejemplosfdw/cronograma.php was not found on this server.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
Que lo que dice es que no existe conograma.php. Y mirando en el listado, el que existe es cronograma.htm.
Saludos.