.tree { margin: 0 0 0 4px; }
.tree,.tree ul {
  list-style-type: none; 
  position: relative;
  padding: 0;
  cursor: default;
  border-left: 1px dotted #ccc;
}
.tree ul {
  margin: 0; 
  display: none;
}
.tree li {
  position: relative;
  margin: 0 0 0 10px;
  padding: 2px 0 2px 0;
}
/* extend a line to the list item */
.tree li:before {
  position: absolute;
  top: 10px; left: -9px; height: 1px; width: 5px;
  border-top: 1px dotted #ccc;
  content: ' '; 
} 

/* erase all lines for last item */
.tree li:last-child:after {
  position: absolute;
  top: 17px; left: -13px; bottom: 0; width: 7px;
  background-color: white;
  content: ' ';
} 
/* add expander widget */
.tree .expander {
  background: #fff url(icons.png) no-repeat scroll;
  background-position: -64px -4px;
  position: absolute;
  top: 8px; left: -15px;
  height: 9px; width: 9px;
  cursor: pointer;
}
.tree .expander:hover { background-color: #eee; }
.tree .expander.expanded { background-position: -78px -4px; }
.tree ul.expanded { display: block; }