Código PHP:
<html>
<head>
<title>Untitled Document</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<script language="JavaScript">
<!--
ns=document.layers
ie=document.all
function esconde() {
if (ie) precarga.style.visibility="hidden";
// if(ns) document.precarga.visibility="hide";
document.location = "http://miweb/web.php";
}
// -->
</script>
</head>
<body onLoad="esconde();" bgcolor="#ffffff">
<div id="ocultar" align="center">
<script>
document.write('<iframe src="http://miweb/web.php" width=20 height=10></iframe>');
</script></div>
<script language="JavaScript">
if (ie) ocultar.style.visibility="hidden";
if(ns) document.ocultar.visibility="hide";
</script>
</body>
<script language="JavaScript">
if(ie || ns) document.write('<div id="precarga" align="center"><img border="0" src="http://miweb/web.php/grafics/imatges/logo.jpg" width="120" height="120"></div>');
</script>
</html>
gracias, saludos