.topbig {
	background-image: url(pic/bgtop.jpg);
	background-repeat: no-repeat;
	background-position: center top;
	background-attachment: fixed;
	position: relative;
}
.dibig {
	background-image: url(pic/dibg.jpg);
	background-repeat: no-repeat;
	background-position: center top;
	background-attachment: fixed;
	position: relative;
}