Noob alert! I was playing around with writing a simple script that would cause a kind of lightbox popup; on clicking a link, a div with several links overlies the page. It's probably full of bad coding, but at least I got something to work.

The main problem I had was that, if an overlay link was clicked, it also triggered the closing of the overlay. I played around with preventDefault(), but that didn't work. Then I stumbled on stopPropagation(), which seems to do the trick.

So here's what I have so far:

Code:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">

<style media="all">
.hide {display: none;}
.view {position: absolute; background: rgba(0,0,0,0.4); text-align: center; top:0; bottom: 0; left: 0; right:0; display: table; width: 100%; height: 100%;}
.view div {display: table-cell; vertical-align: middle;}
#buttons a {display: inline-block; color: white; background: #30353b; text-decoration: none; padding: 10px; border-radius: 10px;}
#buttons a:hover, #buttons a:focus {background: black; color: #e7e7e7;}
#buttons span {display: block; margin-top: 20px; cursor: pointer;}
</style>
</head>
<body>

<p><a id="share" href="#buttons">Share</a></p>

<div id="buttons" class="hide">
	<div>
		<a href="http://facebook.com">Facebook</a>
		<a href="http://twitter.com">Twitter</a>
		<a href="http://google.com">Google</a>

		<span>Exit</span>
	</div>
</div>

<script>
(function () {
	"use strict";
	var d, share, buttons, links, i;
	d = document;
	var share = d.querySelector('#share');
	var buttons = d.querySelector('#buttons');

	share.addEventListener('click', function(event) {
		event.preventDefault();
		buttons.className = 'view';
	}, false);

	buttons.addEventListener('click', function() {
		buttons.className = 'hide';
	}, false);

	links = d.querySelectorAll('#buttons a');
	for(i=0; i<links.length; i++) {
		links[i].addEventListener('click', function(event) {
			event.stopPropagation();
		}, true);
	}
}());
</script>
</body>
</html>
Is there a better way to do this than with stopPropagation()? I don't really understand what it's doing, so if anyone can explain, that would be great. And of course, if there's a better way to go about all this, I'd be happy to know. This is mainly an excuse to learn a bit of JS, although I'm eventually aiming to use this in a project. It's not an essential feature, so in the end, my plan is to create everything in JS and insert it into the HTML. (If JS is off or doesn't fire for some other reason, I'd prefer to have nothing in the HTML.)

PS—I've purposely left out support for older browsers that don't understand modern JS. Eventually I'll add a test for older browsers and just abort the script if they don't understand it.