public function display()
    {
        if (!$this->visible) {
            return;
        }

        parent::display();

        $container_div_tag = new SwatHtmlTag('div');
        $container_div_tag->id = $this->id;
        $container_div_tag->class = $this->getCSSClassString();
        $container_div_tag->open();

        // toggle button content is displayed with JavaScript

        if ($this->valid_range_start === null) {
            $today = new SwatDate();
            $value = $today->formatLikeIntl('MM/dd/yyyy');
        } else {
            $value = $this->valid_range_start->formatLikeIntl('MM/dd/yyyy');
        }

        $input_tag = new SwatHtmlTag('input');
        $input_tag->type = 'hidden';
        $input_tag->id = $this->id . '_value';
        $input_tag->name = $this->id . '_value';
        $input_tag->value = $value;
        $input_tag->display();

        $container_div_tag->close();

        Swat::displayInlineJavaScript($this->getInlineJavaScript());
    }