.tb1 {
	background-attachment: fixed;
	background-image: url(image/bk1.jpg);
	background-repeat: no-repeat;
	background-position: center center;
}
.tb2 {
	background-attachment: fixed;
	background-image: url(image/bk2.jpg);
	background-repeat: no-repeat;
	background-position: right top;
}
.tb3 {
	background-attachment: fixed;
	background-image: url(image/bk3.jpg);
	background-repeat: no-repeat;
	background-position: right top;
}
.tb4 {
	background-attachment: fixed;
	background-image: url(image/bk4.jpg);
	background-repeat: no-repeat;
	background-position: right top;
}
.tb5 {
	background-attachment: fixed;
	background-image: url(image/bk5.jpg);
	background-repeat: no-repeat;
	background-position: right top;
}