function flip(obj, year, id, on) {
	obj.children[0].src	= "../_images/" + year + "/B" + (on ? "D" : "") + year + id + ".gif";	
}

function flipOn(obj, year, id) {
	flip(obj, year, id, true);
}

function flipOff(obj, year, id) {
	flip(obj, year, id, false);
}