Lavoro in locale non saprei come farvela vedere vi posso inviare il codice:

<head>
<title>Home Page</title>
</head>


<body bgcolor="#FFFFFF" text="#000000" leftmargin="0" topmargin="0" marginwidth="0" marginheight="0">
<%
Session("rv") = Request("rv")
%>
<table width="100%" height="100%" border="0" cellpadding="0" cellspacing="0">
<tr>
<td width="100%" height="170">

<table width="100%" height="170" border="0" cellpadding="0" cellspacing="0">
<tr>

<td width="100%" height="170" bgcolor="#CC4519" valign="top" background="File_Flash/Riempi.jpg">

</td>

</tr>
</table
>
</td>
</tr>
<tr>
<td width="<%=Session("rv")%>" align="center" height="100%" bgcolor="#CCCCCC">


<table width="<%=Session("rv")%>" border="0" align="center" cellSpacing="0" cellPadding="0">
<tr valign="bottom" align="center">
<td valign="center" align="right"></td>
</tr>
</table>

<DIV id=content position=relative style="SCROLLBAR-FACE-COLOR: #000000; LEFT: 0px; SCROLLBAR-HIGHLIGHT-COLOR: #000000; OVERFLOW: auto; WIDTH: <%=Session("rv")+40%>px; SCROLLBAR-SHADOW-COLOR: #000000; SCROLLBAR-3DLIGHT-COLOR: #000000; SCROLLBAR-ARROW-COLOR: #979797; SCROLLBAR-TRACK-COLOR: #000000; SCROLLBAR-DARKSHADOW-COLOR: #000000; SCROLLBAR-BASE-COLOR: #000000; TOP: 0px; HEIGHT: 100%">
<table width="<%=Session("rv")%>" height="100%" align="center" border="0" cellpadding="0" cellspacing="0">
<tr>
<td width="<%=Session("rv")%>" valign="top" height="100%">
<div style="font-weight: extra-light; font-size:12px; font-style:normal; font-family:Verdana; color:#214563">




TESTO</p>



bla bla</p>



</p>


</p>


</p>
</div>
</td>
</tr>
</table>
</div>

</td>
</tr>
<tr>
<td width="100%" height="5%">
<table width="100%" height="19" border="0" cellpadding="0" cellspacing="0" bgcolor="#CC4519">
<tr>
<td width="5%" height="19" valign="middle"></td>
<td width="95%" height="19" valign="middle">

<div style="font-weight: extra-light; font-size:9px; font-style:normal; font-family:Verdana; color:#CCFF33">
barra di navigazione</div>
</td>
</tr>
</table>
</td>
</tr>
</table>
</body>
</html>


nella variabile di sessione " session("rv") " passo il valore 860 se il client ha una ris. di 1024x768; 700 se ha un 800x600