/* $formAddAxis = new axis_form(new moodle_url('/mod/assign/feedback/editpdfplus/view_admin.php?id=' . $this->course->id, array('id' => $this->course->id))); //Form processing and displaying is done here
if ($formAddAxis->is_cancelled()) {
//Handle form cancel operation, if cancel button is present on form
} else if ($fromform = $formAddAxis->get_data()) {
//In this case you process validated data. $mform->get_data() returns data posted in form.
$label = $fromform->label;
$axe = $this->addAxis($label);
$formAddAxis->set_data($toform);
return $axe; //"<option>tutu</option>";
} else {
// this branch is executed if the form is submitted but the data doesn't validate and the form should be redisplayed