a ver asi:
Código PHP:
<style type="text/css">
#capa {
width:200px;
height:200px;
position:absolute;
color:#000000;
border:2px solid #000000;
}
</style>
<script type="text/javascript">
function ubicar()
{
var div = document.getElementById('capa');
div.style.left = document.body.clientWidth - 205 + 'px';
div.style.top = document.body.clientHeight - 205 + 'px';
}
</script>
</head>
<body onload="ubicar()">
<div id="capa">ASDFdgsgdg</div>
</body>