Convert a CSS drop down menu in a drop up menu - css

Question

I would like to convert my drop down menu to a drop up menu. I have searched information on the internet, but it didn't help.
My css code:
#nav
{
margin: 0px;
padding: 0px;
position: absolute;
top: 18px;
display: block;
left: 313px;
}
#nav > li
{
list-style-type:none;
float:left;
display:block;
margin:0px 10px;
position:relative;
padding:10px;
width:100px;
}
#nav > li:hover ul
{
display:block;
}
#nav > li:hover
{
-moz-border-radius:10px;
-webkit-border-radius:10px;
}
#nav li ul
{
margin:0px;
padding:0px;
display:none;
}
#nav li ul li
{
list-style-type:none;
margin:10px 0 0 0;
}
#nav li ul li a
{
display:block;
padding:5px 10px;
color:#bdb49f;
text-decoration:none;
}
#nav li ul li:hover a
{
color:#b15815;
-moz-border-radius:5px;
-webkit-border-radius:5px;
}
#nav li span
{
cursor:pointer;
margin:0px 10px;
font-weight:bold;
}

Answer 1

The solution lies in making child ul absolutely positioned.
Here is a working example : http://jsfiddle.net/3NmRP/
The "margin-top" on "#nav" is just here for the sake of example, you can remove it.
#nav{
margin: 0px; padding: 0px; position: absolute; top: 18px; display: block; left: 313px;
}
#nav > li {
list-style-type:none;
float:left; display:block;
margin:0px 10px;
position:relative;
padding:10px;
width:100px;
}
#nav > li ul {
position:absolute;
bottom: 100%;
}
#nav li:hover > ul {
display:block;
}
#nav > li:hover{
-moz-border-radius:10px;
-webkit-border-radius:10px;
}
#nav li ul{
margin:0px;
padding:0px;
display:none;
}
#nav li ul li{
list-style-type:none;
margin:10px 0 0 0;
}
#nav li ul li a{
display:block;
padding:5px 10px;
color:#bdb49f;
text-decoration:none;
}
#nav li ul li:hover a {
color:#b15815;
-moz-border-radius:5px;
-webkit-border-radius:5px;
}
#nav li span{
cursor:pointer;
margin:0px 10px;
font-weight:bold;
}
#nav {
margin-top: 100px;
}