ul.slider{
  list-style: none;
  padding: 0;
  height: 248px;
  width: 400px;
}

ul li.slider_li{
  float: left;
  display: block;
}

ul li span{
  display: block;
  overflow: hidden;
  height: 248px;
  width: 20px;
}

#firstbild{
  width: 400px;
}

ul li img{
  position: absolute;
  height: 248px;
  width: 20px;
}

ul li div{
  margin: 0;
  padding: 0;
  display: block;
  width: 300px;
}