Si fa con una fracassata di script che vanno a modoficare le dimensioni dei frames, l'avevo visto anche un un altro sito qualche tempo fa che ad ogni link si componeva modifciando le dimensioni dei vari frames di cui era composto il frameset.

Questo è il codeice della pagina che hai indicat oe immagino non sarà solo questo:

<html><head>
<title>Benvenuti in Digital Music</title>
<script language="javascript">
function createframe(strName,strURL){
frameobj = eval('document.all.'+strName)
frameobj.src = strURL
try{frameobj.focus();}catch(e){}
}
function loadInitialPage(){createframe('main','');}
</script>


<script language="VBScript" for="window" event="onload">
dim objSonicClient, objApp, blnInstalled, blnInPlugin, blnCurrentShop, blnInWmp, strUrl

blnInPlugin = False

blnInstalled = False
blnCurrentShop = False
blnInWmp = False
On Error Resume Next
blnInWmp = (Len(window.external.version) > 0)
On Error Resume Next
Set objSonicClient = CreateObject("SonicSelectorClient.Config")
If Err.Number = 0 Then
blnInstalled = True
Set objApp = CreateObject("OD2DLEngine.Application")
strShopId = objApp.Shops.CurrentShopID
strDomain = LCase(objApp.Shops(strShopId).DomainName)
Set objApp = Nothing
If Mid(strShopId,4) = "35-2" Then
If StrComp(document.location.hostname,strDomain,vbTex tCompare) = 0 Then
blnCurrentShop = True
End If
End If
End If
if blnInstalled and blnCurrentShop Then
If Not blnInPlugin Then
objSonicClient.SetUrl "/common/frameset/frames.asp?shid=0325002E"
strUrl = objSonicClient.GetUrl(0)
Set objSonicClient = Nothing
If blnInWmp Then
window.location.href = strUrl
Else
window.location.href = "http://sib1.od2.com/editorial/_wanhomepages/shop35/associd2/wmp/sonicstarted.htm"
End If
End If
end if
</script>

</head>

<frameset id=frameset border="0" frameborder="no" framespacing="0" rows="1,*,10" marginheight="0" marginwidth="0">

<frame id="topfuncs" border="0" marginwidth="0" marginheight="0" scrolling="no" frameborder="no" src="topfuncs.asp" >

<frame name="main" id="main" border="0" marginheight="0" marginwidth="0" frameborder="no" src="loading.asp">

<frame id="streamer" border="0" marginheight="0" marginwidth="0" scrolling="no" frameborder="no" src="/common/streamer/frameversion/bot.asp">



</frameset>

<noframes>

</noframes>

</html>