.left_img {
	background-image: url("hanni.jpg");
	background-repeat:no-repeat;
}
.left_img:hover {
	background-image: url("hanni_hover.jpg");
	background-repeat:no-repeat;
}
.right_img {
	background-image: url("martin.jpg");
	background-repeat:no-repeat;
}
.right_img:hover {
	background-image: url("martin_hover.jpg");
	background-repeat:no-repeat;
}