html5 header

HTML

<div class="header"></div>

CSS

.header {
    position:absolute;
    height:10px;
    background:black;
    top:0px;
    left:0px;
    width:100%;
}

JavaScript

$(function () {
    $('.header').hover(function () {
        $(this).stop().animate({
            height: "200px"
        }, 500, 'easeOutBounce');
    }, function () {
        $(this).stop().animate({
            height: "10px"
        }, 500, 'easeOutBounce');
    });
});