Skjul indhold ved klik

var elmVis = null;

function hideElm() {
    if (!elmVis) return;
    elmVis.style.display = "none";
    elmVis = null;
}
function toggle_visibility(id) {
    var e = document.getElementById(id);
    if (e!==elmVis) {
        hideElm();
        e.style.display = 'block';
        elmVis = e;
    }
    else hideElm();
}

if (document.addEventListener) document.addEventListener("click", hideElm, false);
else document.attachEvent("onclick", hideElm);

<script type="text/javascript">
var elmVis = null;

function hideElm() {
    if (!elmVis) return;
    elmVis.style.display = "none";
    elmVis = null;
}
function toggle_visibility(id,evnt) {
    var e = document.getElementById(id);
    if (e!==elmVis) {
        hideElm();
        e.style.display = 'block';
        elmVis = e;
    }
    else hideElm();
    evnt.cancelBubble = true;
    if (evnt.stopPropagation) evnt.stopPropagation();
}

if (document.addEventListener) document.addEventListener("click", hideElm, false);
else document.attachEvent("onclick", hideElm);
</script>
<div>
    <a href="#" onclick="toggle_visibility('foo',event)">Click here to toggle visibility of element #foo</a>
    <div id="foo" style="display: none;">This is foo</div>
</div>
<div>
    <a href="#" onclick="toggle_visibility('bar',event)">Click here to toggle visibility of element #fbar</a>
    <div id="bar" style="display: none;">This is bar</div>
</div>