function faq_start_shortcode( $atts, $content = null ) {
   return '<div id="accordion">';
}

function faq_question_shortcode( $atts, $content = null ) {
   return '<div class="accordionButton">' . $content . '</div>';
}

function faq_answer_shortcode( $atts, $content = null ) {
   return '<div class="accordionContent">' . $content . '</div>';
}

function faq_end_shortcode( $atts, $content = null ) {
   return '</div>';
}

if ( is_single() || is_page() ) {
add_shortcode('faqstart', 'faq_start_shortcode');
add_shortcode('question', 'faq_question_shortcode');
add_shortcode('answer', 'faq_answer_shortcode');
add_shortcode('faqend', 'faq_end_shortcode');
}