$javascript['foot'][]['code'] =  "
                $('form :submit').click(function () {
                    \$(this).
                    prop('disabled', true).
                    closest('form').
                    append(\$('<input/>', {
                        type: 'hidden',
                        name: this.name,
                        value: this.value
                    })).
                    submit();
                    \$(this).addClass('loadingspinner');
                    event.preventDefault();
                });";

.loadingspinner
{
  background:
          url("spin-red.gif")
          no-repeat
          center center;
}