img {
	border: 0px;
}

.menu a {
  display:block;
  background-position:left top;
  background-repeat:no-repeat;
  img-align:right;
  width:250px;
  height:40px;
}
.menu a:hover { background-position: 0 -41px;  }
.menu a#volver1 { background-image: url(../img/volver1.gif) }