window.onload = function() {
	$$('a img').each(function(el){
		el.observe('mouseover',function(){
			new Effect.Opacity(el, { from: 1, to: 0.8,duration: 0 });
		});
	el.observe('mouseout',function(){
			new Effect.Opacity(el, { from: 0.8, to:1,duration: 0 });
		});
	});
}

function descTgl(obj) {
	var desc = obj + "_desc";
	var descAll = obj + "_desc_all";
	Element.toggle(desc);
	Element.toggle(descAll);
}