a.nav span {
  display: none;
}
a.nav:hover span {
  display: block;
  padding: 10px;
  z-index: 100;
  color: #3f4856; 
  background: #dddddd;
  font: 11px Arial, Helvetica, sans-serif;
  border-color: #000000;
	border-width: 0px 1px 1px 0px;
  border-style: solid;
  text-decoration: none;
}
a.nav:hover span.contexthelp {
  position: absolute; 
  top: 290px; 
  left: 150px; 
}