CSS

    body{
     margin: 0;
     background: #444;
    }
    div#header{
     background: url(bgnav.gif);
     position: relative;
     height: 140px;
     border-bottom: 10px solid #fde050;
    }
    div#nav,img#logo{
     position: absolute;
    }
    div#nav{
     top: 103px;
    }
    img#logo{
     left: 43px;
    }
    /* Barra di Navigazione */
    div#nav ul{
     height: 46px;
     overflow: hidden;
     list-style-type: none;
     margin: 0;
     margin-bottom: 0px;
     padding: 0;
     background: url(matrix-menubar.gif) no-repeat;
    }
    
    div#nav li{
     margin: 0;
     padding: 0;
    }
    
    div#nav li,div#nav a{
     float: left;
     margin-top: -1px;
     width: 147px;
     height: 47px;
    }
    div#nav a{
     text-indent: -9000px;
     text-decoration: none;
     padding: 48px 0 0 0;
     overflow: hidden;
     height: 47px; /**/
     background: url(matrix-menubar.gif);
    }
    /* homepage */
    li#homepage a{
     background-position: 0px 0px;
    }  
    li#homepage a:hover{
     background-position: 0 -47px;
    }  
    /* products */
    li#products a{
     background-position: -146px 0px;
    }  
    li#products a:hover{
     background-position: -146px -47px;
    }  
    /* where*/
    li#where a{
     background-position: -292px 0px;
    }  
    li#where a:hover{
     background-position: -292px -47px;
    }  
    /* information*/
    li#info a{
     width: 143px;
     background-position: -440px 0px;
    }  
    li#info a:hover{
     background-position: -440px -47px;
    }

(X)html

  <body id="home">
    <div id="container">
      <div id="header">
        <img alt="image" id="logo" src="logo.gif" />
        <div id="nav">
          <ul>
            <li id="homepage">
              <a title="Homepage" href="#">Homepage</a>
            </li>
            <li id="products">
              <a title="Products" href="#">Products</a>
            </li>
            <li id="where">
              <a title="Where" href="#">Where</a>
            </li>
            <li id="info">
              <a title="Informations" href="#">Info</a>
            </li>
          </ul>
        </div>
      </div>
<div id="css">