<style type="text/css">
#hid {
width: 50px;
height: 50px;
background: #FF0000;
opacity: 0;
position: fixed;
}
body {
height: 1500px;
}
</style>
<body>
<div id="hid"></div>
<script src="http://code.jquery.com/jquery-1.9.1.js"></script>
<script>
$(function () {
var element = $("#hid"), display;
$(window).scroll(function () {
display = $(this).scrollTop() >= 200;
display != element.css('opacity') && element.stop().animate({ 'opacity': display }, 500);
});
});
</script>
</body>
рони,
bo ? , a ?