function attention_hide() {
    var element = document.getElementById('attention');
    element.style.display = 'none';
}

function attention_show() {
    var element = document.getElementById('attention');
    element.style.display = 'block';
}


function externalLinks() {  

    var closebutton = document.getElementById('tt-close');
    closebutton.onclick = function() { attention_hide(); }
     
    var twitter = document.getElementById('twitter-link');
    twitter.onclick = attention_show;
}

window.onload = externalLinks;