Prova così
codice:
<style type="text/css">
/* <![CDATA[ */
#contenitore_generale {
    display: none;
}
/* ]]> */
</style>
<script type="text/javascript">
//<![CDATA[
window.onload = function(){ document.getElementById("contenitore_generale").style.display = "block";}
//]]>
</script>
</head>
<body>