Centering the navigation

[liunx]

I got this navigation codes and put to my standard. I was wondering how do I center the navigation that has text.

Here is the code:

#nav {
font-size: 100%;
background-color: #49342F;
}
#nav ul {
padding: 0 0 0 25px;
margin: 1px ;
text-transform: capitalize;
list-style: none;
background-color: #49342F;
}
#nav ul li {
float: left;
background-color: #49342F;

}
#nav ul li#last a {
border-right: 1px solid #593D3C;


}
#nav ul li a:link, #nav ul li a:visited {
display: block;
padding: 11px 20px 10px 20px;
color:#FFFFFF;
text-decoration: none;
border-left: 1px solid #593D3C;
background-color: #49342F;
}
#nav ul li a:hover {
font-weight:bold;
color: #FFFFFF;
background-color: 442221;
}

I want to center it and not have the right side have more space at the end than the left side. So equal space at the both end sizes.

Also, When ever someone already click to go to that page I want that link to stand out with a bold and the background color of #49342F. How would I go about doing that?

Please help me on this.

Thank youtext-align:center; for IE

#nav ul{
margin:0 auto;

for others