html, body {
  top: 50%;
  left: 0px;
  width: 100%;
  height: 1px;
  overflow: visible;

}
#flashcontent {
	width: 900px;
  height: 450px;
  margin-left: -450px;  /***  width / 2   ***/
  position: absolute;
  top: 0px;          /***  height / 2   ***/
  left: 50%;

}