.UDMenuContainer:hover {
  position: relative;
}
.UDMenuContainer:hover ul.UDMenu {
  display: block;
}

ul.UDMenu {
  width: auto;
  
  list-style-type: none;
  
  display: none;
  position: absolute;
  left: 0px;
  top: 100%;
  padding: 4px;
  margin: 0px;
  white-space: nowrap;
}
ul.UDMenu li {
  padding: 4px;
  margin: 0px;
  
  font-size: 90%;
}
ul.UDMenu li a {
  text-decoration: none;
}
ul.UDMenu li a:hover {
  text-decoration: underline;
}