Modificado de
http://www.zevra.com/experimentos/centrovertical.html Código HTML:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Centrado</title>
<meta http-equiv="Content-Type" content="text/xml; charset=iso-8859-1" />
<style media="screen" type="text/css">
body {
margin:0px;
padding:0px;
}
#linea
{
width: 100%;
position: absolute;
top: 35%;
text-align: center;
overflow: visible;
}
#caja
{
position: absolute;
width: 350px;
height: 252px;
top: -50px;
left: 45%;
margin-left: -100px;
}
</style>
</head>
<body>
<div id="linea">
<div id="caja">
<img src="http://www.guatepredios.com/images/construccion.gif" width="350" height="252" alt="Guatepredios" />
</div>
</div>
</body>
</html>