Button Blogger

    <div id="spoiler" style="display: none;">
    ADD YOUR HIDDEN CONTENT HERE.
    </div>
    <button onclick="if(document.getElementById('spoiler') .style.display=='none') {document.getElementById('spoiler') .style.display=''}else{document.getElementById('spoiler') .style.display='none'}" title="Click to show/hide" type="button">Open/Close</button>
    <br />