body {
  margin: 0px;
  padding: 0px;
  background-color: #cccccc;
}

#outer {width: 100%; height: 100%; position: relative;}
#outer[id] {display: table; position: static;}

#middle {position: absolute; top: 50%;} /* for explorer only*/
#middle[id] {display: table-cell; vertical-align: middle; position: static;}

#inner {position: relative; top: -50%;} /* for explorer only */
/* optional: #inner[id] {position: static;} */