<!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" xml:lang="es" lang="es">
<head>
<meta http-equiv="Content-Type" content="application/xhtml; charset=utf-8" />
<title></title>
<style type="text/css">
body {
font:76% normal verdana,arial,tahoma;
}
#bloqueIzq {
position:absolute;
left:0;
top:8em;
width:10em;
line-height:3em;
background:#99ccff;
border:1px solid #003366;
white-space:nowrap;
padding:0.5em;
}
#bloqueDer {
position:absolute;
right:0;
top:8em;
width:10em;
line-height:3em;
background:#99ccff;
border:1px solid #003366;
white-space:nowrap;
padding:0.5em;
}
</style>
</head>
<body>
<div id="bloqueIzq">
bloque izquierdo
</div>
<div id="bloqueDer">
bloque derecho
</div>
<script type="text/javascript">
var ancho = parseInt(screen.width)/2, intervalo = '';
(fnc = function() {
intervalo = setTimeout(function() {
//var l = parseInt(document.defaultView.getComputedStyle(doc ument.getElementById('bloqueIzq'), null).getPropertyValue('left'));
//var r = parseInt(document.defaultView.getComputedStyle(doc ument.getElementById('bloqueDer'), null).getPropertyValue('right'));
var l = parseInt(document.styleSheets[0].rules[1].style['left']);
var r = parseInt(document.styleSheets[0].rules[2].style['right']);
document.styleSheets[0].rules[1].style['left'] = l+5+'px';
document.styleSheets[0].rules[2].style['right'] = r+5+'px';
if ((l+30) >= ancho) {
clearTimeout(intervalo);
} else {
fnc();
}
},20);
}
)();
</script>
</body>
</html>