.fond {
	background-attachment: fixed;
	background-image: url(images/fond.jpg);
	background-repeat: no-repeat;
	background-position: center center;
}
.centrertab {
	vertical-align: middle;
}
.fond_in {
	background-attachment: fixed;
	background-image: url(images/accueil_22.gif);
	background-repeat: no-repeat;
	background-position: right top;
}