protected function displaySingle(SwatOption $flydown_option)
    {
        $title = $flydown_option->title;
        $value = $flydown_option->value;

        $hidden_tag = new SwatHtmlTag('input');
        $hidden_tag->type = 'hidden';
        $hidden_tag->name = $this->id;

        if ($this->serialize_values) {
            $salt = $this->getForm()->getSalt();
            $hidden_tag->value = SwatString::signedSerialize($value, $salt);
        } else {
            $hidden_tag->value = (string) $value;
        }

        $hidden_tag->display();

        $span_tag = new SwatHtmlTag('span');
        $span_tag->class = 'swat-flydown-single';
        $span_tag->setContent($title, $flydown_option->content_type);
        $span_tag->display();
    }