dropdown navigatie

<!-- B.1 MAIN NAVIGATION -->
      <div class="main-navigation">

        <!-- Navigation Level 3 -->
        <div class="round-border-topright"></div>
        <h1 class="first">Catogorien</h1>

        <!-- Navigation with grid style -->
        <dl class="nav3-grid">
          <dt><a href="#">boeken</a></dt>
            <dd><a href="#">PHP, MYSQL</a></dd>
            <dd><a href="#">HTML, CSS, Javascript</a></dd>
            <dd><a href="#">Overige</a></dd>
          <dt><a href="#">Adobe</a></dt>
          <dt><a href="#">Monitoren</a></dt>
          <dt><a href="#">Accessoires</a></dt>
            <dd><a href="#">Toetsenborden/muizen</a></dd>
            <dd><a href="#">Netwerk/internet</a></dd>
            <dd><a href="#">Tassen</a></dd>            
          <dt><a href="#">Software</a></dt>
              <dd><a href="#">Grafisch</a></dd> 
              <dd><a href="#">Webontwerp</a></dd> 
              <dd><a href="#">Tassen</a></dd> 
          <dt><a href="#">DataOpslag</a></dt>
              <dd><a href="#">Externe hardeschijf</a></dd> 
              <dd><a href="#">USB-Sticks</a></dd> 
              <dd><a href="#">CDs/DVDs</a></dd> 
          <dt><a href="#">Computers</a></dt>
              <dd><a href="#">Notebooks</a></dd> 
              <dd><a href="#">Desktops</a></dd> 
              <dd><a href="#">Apple</a></dd> 
              <dd><a href="#">CDs/DVDs</a></dd> 
        </dl>

.main-navigation {display:inline /*Fix IE floating margin bug*/; float:left; width:200px; overflow:visible !important /*Firefox*/; overflow:hidden /*IE6*/;}

.main-navigation .round-border-topright {width:10px; height:10px; position:absolute; z-index:10; margin:0 0 0 190px; background:url(../img/bg_corner_topright.gif) no-repeat;}


.nav3-grid {width:199px; border-bottom:solid 1px rgb(200,200,200);}
.nav3-grid dt a, .nav3-grid dt a:visited {display:block; min-height:2.0em /*Non-IE6*/; height:auto !important; height:2.0em /*IE6*/; line-height:2.0em; padding:0px 10px 0px 20px;  border-top: solid 1px rgb(200,200,200); text-decoration:none; color:rgb(70,122,167); font-weight:bold; font-size:120%;}
.nav3-grid dd a, .nav3-grid dd a:visited {display:block; min-height:1.7em /*Non-IE6*/; height:auto !important; height:1.7em /*IE6*/; line-height:1.7em; padding:0px 10px 0px 40px; border:none; font-weight:normal; text-decoration:none; color:rgb(70,122,167); font-size:120%;}
.nav3-grid dt a:hover, .nav3-grid dd a:hover {background-color:rgb(225,225,225); color:rgb(42,90,138); text-decoration:none;}