div#sponsor_banner
{
  display: block;
  position: relative;
  width: 100%;
  margin-bottom: 6px;
  padding-top: 20%;
/*  z-index = 5; */
}

div#sponsor_banner a
{
  display: block;
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  padding-top: 20%;
  /* background-image:  set with javascript */
  background-repeat: no-repeat;
  background-size: cover;
  background-position: center;
  border: 2px solid gray;
  border-radius: 8px;
  cursor: pointer;
  -webkit-transition: opacity 3s ease-in-out;
  -moz-transition: opacity 3s ease-in-out;
  -ms-transition: opacity 3s ease-in-out;
  -o-transition: opacity 3s ease-in-out;
  transition:opacity 3s ease-in-out;
}