CSS: how to add a down arrow for the active link - css

Question

![enter image description here][1]I have the following CSS navigation that adds an arrow on hover.
How can add an arrow to be visible for the active or on link? i have attached the image as well
Here is my code below
<style type="text/css">
#nav {
margin-top:0;
padding: 12px 0;
margin-left: 0;
background-color: #fafafa;
color: #464646;
-moz-box-shadow: 0 5px 5px #888;
-webkit-box-shadow: 0 5px 5px #888;
box-shadow: 0 5px 5px #888;
}
#nav li {
list-style: none;
display: inline;
margin: 0px;
padding: 0;
padding: 22px;
padding-right: 0;
padding-left: 0;
}
#nav li a {
font-family: Arial;
font-style:normal;
text-transform: uppercase;
text-decoration: none;
color: #464646;
padding: .7em 3em;
border-right: 1px dashed #959595;
}
#nav li a:hover {
background-color: #fafafa;
color: #005596;
font-weight: bold;
}
#nav li:hover {
background: transparent url(images/down_arrow2.png) no-repeat scroll center bottom;
margin: 0;
}
#active a:link, #active a:visited,#active a:hover
{
/* border: 1px solid #333; */
background-color: #fafafa;
color: #005596;
font-weight:bold;
}
</style>
HTML
<ul id="nav">
<li id="active">Home</li>
<li>Photos</li>
<li>Videos</li>
<li>Add a Restaurant</li>
<li>Delete a Restaurant</li>
<li>Logout</li>
</ul>

Answer 1

Use a class name instead if an id:
<li class="active">Home</li>
Then you can do:
#nav li.active {
background: transparent url(images/down_arrow2.png) no-repeat scroll center bottom;
margin: 0;
}

Answer 2

Just add a background image to css.
#active a:link, #active a:visited,#active a:hover
{
/* border: 1px solid #333; */
background-color: #fafafa;
color: #005596;
font-weight:bold;
background: transparent url(images/down_arrow2.png) no-repeat center bottom;
margin: 0;
}