Con le table riesco a ottenere la pagina al centro in qualsiasi risoluzione...ma con i div come faccio?


codice:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>PIPPO</title>
</head>
<body style="margin-left:0px; margin-top:0px; margin-right:0px; margin-bottom:0px; padding:0px">
<table cellpadding="0" cellspacing="0" border="0"  align="center" style="width:100%; height:100%">
	<tr>	
	  <td align="center" valign="middle" style="height:100%">PIPPOPLUTO</td>
	</tr>
</table>
</html>