/* CSS Document */

.bg_menu {
	background-image:url(../imgs/mn_top_cor.gif);
	background-repeat:repeat-x;
	width: 565px;
	height: 30px;
}
.spacer_miolo_menu {
	width: 574px;
	height: 30px;
}
.canto_menu {
	width: 9px;
	height: 30px;
	background-image: url(../imgs/mn_top_canto.gif);
	background-repeat: no-repeat;
}
.separacao_menu {
	background-image:url(../imgs/mn_top_separacao.gif);
	background-repeat:no-repeat;
	width: 6px;
	height: 30px;
	background-position: center center;
}
.menu_principal {
	font-family:Georgia, "Times New Roman", Times, serif;
	font-size:14px;
	color:#333333;
	text-decoration:none;
}
.menu_dropdown {
	font-family:Georgia, "Times New Roman", Times, serif;
	font-size:11px;
	color:#333333;
	text-decoration:none;
}
.fonte_tabela {
	font-family:Georgia, "Times New Roman", Times, serif;
	font-size:14px;
	color:#333333;
	text-decoration:none;
	font-weight: bold;
}

.texto_padrao{
	font-family:Georgia, "Times New Roman", Times, serif;
	font-size:14px;
	color:#333333;
}
a.link_interno{
	font-family:Georgia, "Times New Roman", Times, serif;
	font-size:14px;
	color:#333333;
}
.menu_lat{
	font-family:Georgia, "Times New Roman", Times, serif;
	font-size:14px;
	color:#333333;
	text-decoration:none;
}
ul {
	margin: 0;
	padding: 0;
	list-style: none;
	width: 150px;
	}
ul li {
	position: relative;
	}
li ul {
	position: absolute;
	left: 149px;
	top: 0;
	display: none;
	}
ul li a {
	display: block;
	text-decoration: none;
	color: #777;
	background: #fff;
	padding: 5px;
	border: 1px solid #ccc;
	border-bottom: 0;
	}
/* Fix IE. Hide from IE Mac \*/
* html ul li { float: left; }
* html ul li a { height: 1%; }
/* End */
ul {
	margin: 0;
	padding: 0;
	list-style: none;
	width: 150px;
	border-bottom: 1px solid #ccc;
	}
li:hover ul { display: block; }
startList = function() {
if (document.all&&document.getElementById) {
navRoot = document.getElementById("nav");
for (i=0; i<navRoot.childNodes.length; i++) {
node = navRoot.childNodes[i];
if (node.nodeName=="LI") {
node.onmouseover=function() {
this.className+=" over";
  }
  node.onmouseout=function() {
  this.className=this.className.replace
	(" over", "");
   }
   }
  }
 }
}
window.onload=startList;

li:hover ul, li.over ul { 
	display: block; }
<ul id="nav">
/* Fix IE. Hide from IE Mac \*/
* html ul li { float: left; height: 1%; }
* html ul li a { height: 1%; }
/* End */