Gracefully terminates the form and shows a message plus opionally a 
CONTINUE button for further redirection.

Call:

    ff_die($message=null, $action='stop', $target='', $params='', $label='Continue');
    return;

    $message = A message to display. If no message is provided, it will
               display:

                    Fatal error in $formname, processing stopped.

    $action  = 'stop' : Dont show a CONTINUE button (default)
               'self' : Redirect to the same form
               'form' : Redirect to another form 
               'page' : Redirect to another page of this site
               'home' : Redirect to homepage of the site
               'url'  : Redirect to a url

    $target  = Target name/url for 'form', 'page' and 'url'

    $params  = Additional parameters for 'self' and 'form'

    $label   = Text for the continue button

Examples:

    // Display standard message without continue button
    ff_die(); 

    // Display message without continue button
    ff_die('Sorry, cannot continue for some reason.');

    // Display standard message and return to same form with a parameter
    ff_die(null, 'self', '&ff_param_foo=bar');

    // Redirect to another form
    ff_die('Guess you are hungry now...', 'form', 'SamplePizzaShop', null, 'Order');

    // Redirect to another site page
    ff_die(
        'Something strange has happened!', 
        'page', 
        'index.php?option=com_content&task=section&id=1&Itemid=2'
    );