#soubahyou{
	background:url(../images/souba_over.png);
	position:relative;
	overflow:hidden;
	width:650px;
	height:340px;
}
#soubahyou a{
	width:650px;
	height:340px;
	display:block;
}
#soubahyou a:hover img{
  position:relative;
	top:-340px;
}