#gal45sb {
  width:632px;
  height:424px;
}
#gal45bg {
  background:#ccc;
  border:2px outset #000052;
  text-align:left;
  padding:8px;
}
#gal45vp {
  width:612px;
  height:404px;
  top:0px;
  left:0px;
}

#gal45vp {
  position:relative;
}
#gal45vp a, #gal45vp span {
  position:absolute;
}
#gal45bg, #gal45sb {
  position:static;
}
#gal45vp span.imgbigi, #gal45vp span.imgsmli, #gal45vp span.imgdescm, #gal45vp span.imgdesci {
  position:static;
}
#gal45vp * {
  text-decoration:none;
}
#gal45vp span.imgsmlo, #gal45vp span.imgbigo, #gal45vp span.xxl {
  background:#fff no-repeat center;
  border:2px outset #000052;
}
#gal45vp a:hover span.imgsmlo, #gal45vp span.imgbigo {
  border-style:groove;
}

#gal45vp span.imgbigo {
  right:0px;
  top:0px;
  background:url('http://www.pixels4u.de/images/content/hp/ldg.gif') no-repeat center;
}
#gal45vp span.imgbigi {
  left:0px;
  top:0px;
  width:0px;
  height:0px;
  background:no-repeat center;
  cursor:default;
}

#gal45vp a:hover span.imgbigi, #gal45vp a#gal45b00 span.imgbigi {
  width:400px;
  height:400px;
}

#gal45vp a {
  display:block;
  cursor:default;
}
#gal45vp span.area, #gal45vp span.imgbigo, #gal45vp span.imgbigi, #gal45vp span.imgsmlo, #gal45vp span.imgsmli, #gal45vp span.imgdesci, #gal45vp span.imgdescm, #gal45vp span.imgdesco {
  display:block;
}
#gal45vp span.area {
  visibility:hidden;
  width:0;
  height:0;
}
#gal45vp a:hover span.area, #gal45vp a#gal45b00 span.area {
  visibility:visible;
  width:100%;
  height:100%;
}
#gal45vp a {
  z-index:3;
}
#gal45vp a:hover {
  z-index:2;
}
#gal45vp a#gal45b00 {
  z-index:1;
}
#gal45bg, #gal45vp {
  z-index:0;
}
<!-- (Positionierung XXL-Zeichen) -->
#gal45vp span.xxl {
  padding:1px;
  right:-4px;
  bottom:-4px;
  font-size:8px;
  line-height:1em;
  color:#000;
  font-family:arial,sans-serif;
  text-align:center;
  cursor:pointer;
}

#gal45vp span.imgdesco {
  left:0px;
  bottom:0px;
  width:200px;
  height:21px;
  background:#fff;
}
#gal45vp span.imgdescm {
  padding:2px;
  border:2px groove #fff;
}
<!-- (Textzeile) --> <!-- (Textzeile) -->
#gal45vp span.imgdesci {
  width:192px;
  height:13px;
  font-family:verdana,sans-serif;
  font-size:11px;
  line-height:13px;
  font-style:normal;
  color:#000;
  white-space:nowrap;
  overflow:hidden;
  cursor:default;
}

.hint {
  width:616px;
  text-align:center;
  font-size:10px;
  color:#999;
  font-family:verdana,sans-serif;
}

#gal45vp span.imgsmli { width:60px; height:60px; }
#gal45vp a { width:64px; height:64px; }
#gal45vp span.area { left:0px; top:0px; }
#gal45vp span.imgsmlo, #gal45vp span.imgsmli { left:0px; top:0px; }

a#gal45b01, a#gal45b01:hover span.imgsmlo { left:0px; top:0px; }
a#gal45b02, a#gal45b02:hover span.imgsmlo { left:68px; top:0px; }
a#gal45b03, a#gal45b03:hover span.imgsmlo { left:136px; top:0px; }
a#gal45b04, a#gal45b04:hover span.imgsmlo { left:0px; top:68px; }
a#gal45b05, a#gal45b05:hover span.imgsmlo { left:68px; top:68px; }
a#gal45b06, a#gal45b06:hover span.imgsmlo { left:136px; top:68px; }
a#gal45b07, a#gal45b07:hover span.imgsmlo { left:0px; top:136px; }
a#gal45b08, a#gal45b08:hover span.imgsmlo { left:68px; top:136px; }
a#gal45b09, a#gal45b09:hover span.imgsmlo { left:136px; top:136px; }
a#gal45b10, a#gal45b10:hover span.imgsmlo { left:0px; top:204px; }
a#gal45b11, a#gal45b11:hover span.imgsmlo { left:68px; top:204px; }
a#gal45b12, a#gal45b12:hover span.imgsmlo { left:136px; top:204px; }
a#gal45b13, a#gal45b13:hover span.imgsmlo { left:0px; top:272px; }
a#gal45b14, a#gal45b14:hover span.imgsmlo { left:68px; top:272px; }
a#gal45b15, a#gal45b15:hover span.imgsmlo { left:136px; top:272px; }

#gal45vp a:hover, #gal45vp a#gal45b00 {
  left:0px;
  top:0px;
  width:612px;
  height:404px;
}