.start_left_flash{
  /*border: 1px solid black;*/
  width: 512px;
  height: 340px;
  position: relative;
  top: -1px;
  float: left;
  background-color: #ffd900;
} 
.start_right_flash{
  /*border: 1px solid black;*/
  float: left;
  width: 164px;
  height: 340px;
}