#wb_tree span{
   border: 1px solid gray;
   padding: 0 3px;
   margin-right: 3px;
   cursor: pointer;
}
#wb_tree ul{
	list-style: none;
}
#wb_tree ul li{
   margin-left: 10px;
}
#wb_tree ul ul{
   margin-left: 10px;
}
#wb_tree ul ul li{
   background-image: url(li-b.png);
   background-repeat: no-repeat;
   background-position: left;
   padding-left: 5px;
}