Sfondo in trasparenza

Ciao a tutti!

Ho già fatto un sito con box in trasparenza, questo:

http://www.programmarealpc.altervista.org

(non si vede con mozilla firefox)

Ma facendone un altro mi sono ritrovato con un piccolo problema: non riesco a capire dove inserire

Codice:

---

opacity: .7;
filter: alpha(opacity=70);

---

nel css del nuovo sito.

Come e dove posso mettere la trasparenza sapendo che il codice css è:

Codice:

---

body {
        margin-left: 0px;
        margin-top: 0px;
        margin-right: 0px;
        margin-bottom: 0px;
          margin: 0px;
  scrollbar-face-color: #A9BAC3 ;
  scrollbar-highilight-color: #A9BAC3;
  scrollbar-shadow-color: #A9BAC3;
  scrollbar-tredlight-color: #A9BAC3;
  scrollbar-arrow-color: #ffffff;
  scrollbar-track-color: #FC8DE;
  scrollbar-dark-shadow-color: #000000
}

.testopagine {
        font-family: Verdana, Arial, Helvetica, sans-serif;
        font-size: 12px;
        font-weight: bold;
        color: #FFAD5A;
        background:#999999
}


.menuleft {
        border-right: 0px solid Black;
        border-left: 0px solid Black;
        border-top: 1px solid Black;               
        vertical-align: top;
        text-align: center;       
        align: left;
        width: 200px;
        height: 500px;               
}

.menuright {
        width: 200px;
        height: 500px;       
        vertical-align: top;
        text-align: center;
        border-top: 1px solid Black;       
        border-left: 0px solid Black;
        border-right: 0px solid Black;               
}
.titoli {
        font-family: Verdana, Arial, Helvetica, sans-serif;
        font-size: 15px;
        font-weight: bold;
        color: #000000;

}

/* si modifica il colore del powerd */
A.linkpowerd  {
        text-decoration : none;
        color : #000000;
        font-size : 10px;
        font-weight : bold;
; font-family: Verdana, Arial, Helvetica, sans-serif
}

/* si modifica colore scritte footer */
A.menufooter {
        color: #000000;
        text-decoration: none;
        font-family: Verdana, Arial, sans-serif;
        font-size: 12px;
        font:bold;
       
}

.rose table {
        font-family: Arial, sans-serif;
        font-size: 12px;
        border-collapse: collapse;
        border: 0px Solid Black;/**/
        background-color: #AAF07A;       
}


.intestazione table td {
        font-family: Arial, sans-serif;
        font-size: 12px;
        vertical-align: top;
}


.calendario table {
        font-family: Arial, sans-serif;
        font-size: 12px;
        border-collapse: collapse;
        border: 0px Solid Black;/**/
        /*background-color: #AAF07A;*/
}

.menulogin {
        color: #ffffff;
        text-decoration: none;
        font-family: Verdana, Arial, sans-serif;
        font-size: 12px;

TR.header {
  background: #0160C9;
}

TR.headerNavigation {
  background: #0160C9;
}

TD.headerNavigation {
  background: url('template/images/sfondo_navigazione.gif');
  color: #ff22ff;
  font-weight : bold;
}

TD.headerNavigation2 {
  background: url('template/images/sfondo_navigazione_destra.gif');
  color: #ff33ff;
  font-weight : bold;

}

A.headerNavigation {
        color: #ffffff;
        font-family: Verdana, Arial, sans-serif;
  font-size: 10px;

}

A.headerNavigation:hover {
        color: yellow;
        font-family: Verdana, Arial, sans-serif;
  font-size: 10px;
}

TR.headerError {
  background: #ff0000;
}

TD.headerError {
  font-family: Tahoma, Verdana, Arial, sans-serif;
  font-size: 12px;
  background: #ff0000;
  color: #ffffff;
  font-weight : bold;
  text-align : center;

}

TR.headerInfo {
  background: #00ff00;
}

TD.headerInfo {
  font-family: Tahoma, Verdana, Arial, sans-serif;
  font-size: 12px;
  background: #00ff00;
  color: #ffffff;
  font-weight: bold;
  text-align: center;
}



TD.footer_text {
        font-family: Verdana, Arial, sans-serif;
        font-size: 10px;/* modificato in origine era  #B6B6B6  */
        background: #074c5a;
        color: #EBEB17;
        font-weight: bold;
}
.menu {
        font-family: Verdana, Arial, Helvetica, sans-serif;
        font-size: 16px;
        font-weight: bold;
        color: #000000;
        background-color: #AFC7DD;
        text-align: center;
        margin: 0px;
        padding: 0px;
        border-top-width: 3px;
        border-right-width: 3px;
        border-bottom-width: 4px;
        border-left-width: 2px;
        border-top-style: solid;
        border-right-style: solid;
        border-bottom-style: solid;
        border-left-style: solid;
        border-top-color: #0160C9;
        border-right-color: #0160C9;
        border-bottom-color: #0160C9;
        border-left-color: #0160C9;
}
A.linkMenu  {
        color : #003466;
text-decoration : none;
        font-size : 12px;
        font-weight : bold;
font-family: Verdana, Arial, Helvetica, sans-serif;
}

---

e quello della pagina è:

Codice PHP:

---

<?php
include("template/configure.php");
?>

<!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=utf-8" />
<link rel="stylesheet" type="text/css" href="stylesheet.css">
<title>FANTAWILLOS.NET</title>
<script src="fixedbackground.js" type="text/javascript"></script>
</head>

<!--INIZIO BODY PAGINA -->

<body marginwidth="0" marginheight="0" topmargin="0" bottommargin="0" leftmargin="0" rightmargin="0" onload="fixedBackground('immagini/sfondo.jpg');">
<div align="center">
<center>
<table width="<?php echo $larghezza_sito; ?>" background="<?php echo $immagine_sfondo_centrale; ?>" bgcolor="<?php echo $colore_sfondo_centrale; ?>" border="0" cellpadding="0" cellspacing="0" style="border-collapse: collapse" bordercolor="#111111" id="AutoNumber1">
<tr>
<td height="100%" >
<!-- header //-->
<?php
//BARRA ALTA HEADER
include('includes/header.php');
?>
<!-- header_eof //--></td>
</tr>
</table>
<table width="900" border="1" align="center">
<td width="900">

<?php
//testopagine
include('testo/index.php');
?></td>
<td width="5"><td class="menuright">
<div>
<?php
include("main_login.php");
?>
</div></td>
</tr>
</table>

<?php
include('includes/footer.php');
?>
</body>
</html>

---

Magari aggiungendo un div con id contenitore come ho fatto qui:

Guarda sorgente pagina dal browser, c'erano troppi caratteri e il sorgente qui non ci stava. http://www.programmarealpc.altervista.org

e il css:

Codice:

---

body {text-align:center; font-family:Helvetica, arial, sans-serif; font-size:12px; margin:0;}
 a img {border:0;}
 div#contenitore {background:#180000; width:915px; margin:0 auto; text-align:justify; opacity: .7; filter: alpha(opacity=70);}
  div#header {height:170px;}
  div#header h1, div#header h2 {text-align:center; margin-left:510px;}
  div#header h1 { margin-top:0; padding-top:1em; color:#FFF;}
    div#header h1 a {color:#FFF;}
  div#header h2 {color:#F60;}
  div#colsx {background:#F60; width:766px; \width:767px; w\idth:766px; float:left; border-right:1px solid #CCC; }
  ul#menu {background:#999; padding:0; margin:0; list-style:none; height:2.75em; border-width:0.1em 0; border-color:#333; border-style:solid;}
    ul#menu li {float:left;}
    ul#menu li a {display:block; color:#FFF; background:#999; font-size:1.1em; line-height:2.5em; padding:0 1.5em; text-decoration:none; border-right:0.08em solid #333; font-family:Verdana, sans-serif; font-weight:bold;}
    ul#menu li a.current {background:#300000;}
    ul#menu li a:hover {background:#F60;}
  div#subcolsx { background:#FFF; float:left; width:598px; \width: 619px; w\idth:598px; padding:10px; border-right:1px solid #000;}
  div#subcoldx {background:#F60; color:#180000; width:127px; \width: 147px; w\idth:127px; float:left; padding:10px; text-align:center; margin-top:1em;}
  div#subcoldx {margin-top:0;}
  div#subcoldx img {border:2px outset #180000;}
 div#coldx {background:#180000; color:#FFF; width:127px; \width: 148px; w\idth:127px; float:left; padding:10px; border-top:1px solid #333; }
 div#footer {background:#333; text-align:center; border-top:6px solid #CCC; color:#F60; font-style:italic;}

 h1, h2, h3, h4, h5, h6 {font-family:Georgia, serif; }
 h1 {font-size:2.5em;}
 h2 {font-size:1.8em;}
 h3 {font-size:1.6em;}
 h4 {font-size:1.4em; font-style:italic;}
 h5 {font-size:1.2em; font-style:italic;}
 h6 {font-size:1.1em; font-style:italic;}
 .clearlft {clear:left; }

---

Grazie.