Drop-down menu using CSS

Dropdown menu html

<!-- This code goes in your HTML page to replace your current menu.
Note that the dropdown part is a ul inside of the li tags -->
<nav id="dropdown"> <ul> <li><a href="index.html">HOME</a></li> <li><a href="#">SECOND PAGE</a></li> <li><a href="#">THIRD PAGE</a></li> <li><a href="#">THREAD 1</a> <ul> <li><a href="#">THREAD 1, P 1</a></li> <li><a href="#">THREAD 1, P 3</a></li> <li><a href="#">THREAD 1, P 3</a></li> </ul> </li><!-- end thread 1 --> <li><a href="#">THREAD 2</a> <ul> <li><a href="#">THREAD 1, P 1</a></li> <li><a href="#">THREAD 1, P 3</a></li> <li><a href="#">THREAD 1, P 3</a></li> </ul> </li><!-- end thread 2 --> <li style="border-width:0;"> <a href="#" style="border-width:0;">FOURTH PAGE</a></li> </ul> </nav><!-- dropdown --> <div class="clear"></div>

Drop-down menu CSS

/********************************************
DROP DOWN MENU STYLES FOR CSS PAGE. You can adjust
the background-color and color specs to your liking.
********************************************/
#dropdown
	{
	border: 0px;
	margin: 0px;
	padding: 0px;
	font-size: 9pt;
	text-transform: uppercase;
	}
#dropdown ul
	{
	background: #900;
	height: 40px;
	list-style: none;
	margin: 0;
	padding: 0;
	border-top: 1px #900 solid;
	}
#dropdown li
	{
	float:left;
	padding:0px;
	margin: 0;
	font-size: 9pt;
	}
#dropdown a
	{
	background: #900;
	color: #FFF;
	display: block;
	font-weight: normal;
	line-height: 40px;
	margin: 0px;
	padding: 0px 25px;
	text-align: center;
	text-decoration: none;
	border-right: 1px #FFF solid;
	}
#dropdown a:hover
	{
	background-color: #009;
	color:#FFF;
	text-decoration:none;
	}
#dropdown li ul
	{
	background:#900;
	display:none;
	height:auto;
	padding:0px;
	margin:0px;
	border:0px;
	position:absolute;
	width:225px;
	z-index:200;
	/*top:1em;
	/*left:0;*/
	}	
#dropdown li:hover ul
	{
	display:block;
	}
#dropdown li li
	{
	display: block;
	float: none;
	margin: 0px;
	padding: 0px;
	width: 225px;
	border-top: 1px #FFF solid;
	border-right:0 #FFF solid;
	}
#dropdown li:hover li a
	{
	background:none;
	border-width:0;
	}
#dropdown li ul a
	{
	display:block;
	height:35px;
	font-size:8.5pt;
	font-style:normal;
	margin:0px;
	padding:0px 10px 0px 15px;
	text-align:left;
	}
#dropdown li ul a:hover, #menu li ul li:hover a
	{
	background-color:#009;
	border:0px;
	color:#FFF;
	text-decoration:none;
	}
#dropdown p
	{
	clear:left;
	}