ul {
list-style-type:none;
margin:0;
padding:0;
width:600px00px;
}

li {
    float: left;
    text-align:center;
}

li.active{
    background-color:gray;
}

a {
    text-decoration:none;
    color:#fff;
    display:block;
    width:100px;
}

a:hover {
    background:gray;
}

#nav_links {
    margin:50px auto;
    position:relative;
    width:620px;
}


#slides { 
    margin:0px auto;
    position: relative; 
    width: 800px; 
    height: 600px; 
    background:#000;
   /* background:#ffff; */
    box-shadow: 0 0 25px rgba(0,0,0,0.4); 
}

#slideshow  { 
    position: relative; 
    top: 10px; 
    left: 0px; 
    right: 0px;
    bottom:10px;
    
}