function _centrerSite(element)
{
	l=$(window).width(); h=$(window).height();
	lSite = $(element).width(); hSite = $(element).height();
	margeLeft = (l-lSite)>>1; margeTop = 3*((h-hSite)>>3);
	if (margeLeft<0) margeLeft=0; if (margeTop<0) margeTop=0;
	$(element).css("left", margeLeft+"px").css("top", margeTop+"px");
}