<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Test</title>
<link rel="stylesheet" href="styles.css" type="text/css" />
<script src="http://code.jquery.com/jquery-latest.min.js"></script>
<script type="text/javascript">
$(document).ready(function () {
$("div").hide();
$("#butt").toggle(
function(){$("div").slideDown("slow");},
function(){$("div").slideUp("slow");}
);
});
</script>
</head>
<body>
<span id="butt">BUTTON</span>
<div >TEST_LEFT</div>
</body>
</html>
http://api.jquery.com/