Ke tal Marti pruebate este script
<!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">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Documento sin título</title>
</head>
<body>
<table width="616" border="0" cellpadding="0" cellspacing="0">
<!--DWLayoutTable-->
<tr>
<td width="147" height="351" valign="top"><table width="100%" border="0" cellpadding="0" cellspacing="0">
<!--DWLayoutTable-->
<tr>
<td width="147" height="351"><a href="javascript:jumpto('index.php')">LINK</a></td>
</tr>
</table>
</td>
<td width="469">
<!-- FRAME DE VISUALIZACION CENTRAL -->
<script language="JavaScript">
var displaymode=0
var iframecode='<iframe id="external" style="width:100%;height:100%" src="PAGINACENTRAL.HTM" frameBorder=0> </iframe>'
if (displaymode==0)
document.write(iframecode)
function jumpto(inputurl){
if (document.getElementById&&displaymode==0)
document.getElementById("external").src=inputurl
else if (document.all&&displaymode==0)
document.all.external.src=inputurl
else{
if (!window.win2||win2.closed)
win2=window.open(inputurl)
else{
win2.location=inputurl
win2.focus()
}}}
</script>
</td>
</tr>
</table>
</body>
</html>