Prova così:
codice:
<html>
<head>
<title>Untitled Document</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<script language="JavaScript">
<!--
function MM_checkPlugin(plgIn, theURL, altURL, autoGo) { //v4.0
  var ok=false; document.MM_returnValue = false;
  with (navigator) if (appName.indexOf('Microsoft')==-1 || (plugins && plugins.length)) {
    ok=(plugins && plugins[plgIn]);
  } else if (appVersion.indexOf('3.1')==-1) { //not Netscape or Win3.1
    if (plgIn.indexOf("Flash")!=-1 && window.MM_flash!=null) ok=window.MM_flash;
    else if (plgIn.indexOf("Director")!=-1 && window.MM_dir!=null) ok=window.MM_dir;
    else ok=autoGo; }
  if (!ok) theURL=altURL; if (theURL) window.location=theURL;
}
//-->
</script>
</head>

<body bgcolor="#FFFFFF" text="#000000" onLoad="MM_checkPlugin('Shockwave Flash','banner.swf','immagine.gif',false);return document.MM_returnValue">
</body>
<script name="Used by MM_checkPlugin" language="javascript">
<!--
with (navigator) if (appName.indexOf('Microsoft')!=-1 && appVersion.indexOf('Mac')==-1) document.write(''+
'<scr'+'ipt language="VBScript">\nOn error resume next\n'+
'MM_dir = IsObject(CreateObject("SWCtl.SWCtl.1"))\n'+
'MM_flash = NOT IsNull(CreateObject("ShockwaveFlash.ShockwaveFlash"))\n</scr'+'ipt>');
//-->
</script>
</html>
Le voci da sostituire con i tuoi file, sono in grassetto.

Oppure segui le guide che ti ha consigliato Yassassin!
:gren: