public function edit_field_add($mform) {
        $size = $this->field->param1;
        $maxlength = $this->field->param2;
        $fieldtype = ($this->field->param3 == 1 ? 'password' : 'text');

        // Create the form field.
        $mform->addElement($fieldtype, $this->inputname, format_string($this->field->name), 'maxlength="'.$maxlength.'" size="'.$size.'" ');
        $mform->setType($this->inputname, PARAM_TEXT);
    }