Click Events, lol, wut

<!DOCTYPE html>
<html>
    <head>
        <title></title>
        <style>
            div {
                margin:5px;
                width:900px;
                height:100px;
                font:30px 'Comic Sans';
                color:#fff;
                background:magenta;
                position:absolute;
            }
            #wut {
                background:cyan;
            }
        </style>
    </head>
    <body>
        <div id='wut'>wut</div>
        <div id='lol'>lol</div>
        <script>
            // fully-featured jquery replacement mobile ready blah blah
            function $(x) {
                var d = (x[0] !== '.') ? document.getElementById(x) : document.getElementsByClassName(x.slice(1));
                d.on = function(x, c) {
                    if (d.length) for (var i = 0; i < d.length; i++) d[i].addEventListener(x, c);
                    else d.addEventListener(x, c);
                    return d;
                }
                return d;
            }
            function say(e) { alert('clicked') }
            $('lol').on('mousedown', function() {
                $('wut').style.zIndex=2;
            }).on('click', say);
        </script>
    </body>
</html>