ปัญหาการทำเมนู css hor ให้ active ใช้งานได้ถูกทุกเมนู ค่ะ

<?
include('connectdb.php');
$strSQL = "SELECT * FROM category";
$objQuery = mysql_query($strSQL) or die ("Error Query [".$strSQL."]");
?>

<div id="wrapper">
<ul id="nav">
<? 
while($objResult = mysql_fetch_array($objQuery))
{
	$name = $objResult["Name"];

?>
	<li><a href="Page.php?Category=<?=$name?>"><? echo $name ?></a></li>

<?
	}
  ?>
  </ul>
  </div>
<?
mysql_close();
?>

#wrapper {
	width: 800px;
	float: right;
	margin-top: 15px;
}

#nav, ul#nav li {
	float: left;
}
ul#nav li {
	list-style-type: none;
	background-repeat: no-repeat;
	overflow: hidden;
	margin-right: 5px;
}

ul#nav li a {
	display: block;
	width: 110px;
	height: 40px;
	text-align: center;
	padding-top: 20px;
	padding-bottom: 20px;
	color: #FFF;
	font-weight: normal;
	text-decoration: none;
	text-transform: uppercase;
	font-size: 16px;
	font-style: normal;
	text-shadow: 0px 2px 2px #000;
	overflow: hidden;
}

ul#nav li a:hover {
	color: #fff;
	font-style: normal;
	font-weight: normal;
	background-image:url(../images/1307812721_next.png);
	background-repeat: no-repeat;
	background-position: center top;
	overflow: visible;
}

ul#nav li a:active {
	position: relative;
	top: 2px;
}


ul#nav li#active a {
color: #FFF;
	background-image:url(../images/a2.gif);
	background-repeat: no-repeat;
	background-position: center top;
}