window.addEvent('domready', function(){
	var img_opacity = {
		'mousedown': function(){
			this.setStyle('opacity', .5);
		},
		'mouseup': function(){
			this.setStyle('opacity', 1);
		},
		'mouseleave': function(){
			this.setStyle('opacity', 1);
		}
	};
	
	$$('a').each(function(el){
		var img = el.getElement('img');
		if (!img ) return;
		el.addEvents(img_opacity);
	});
	
	$$('input[type=image]').each(function(el){
		el.addEvents(img_opacity);
	});
	
	$$('a.main_menu').each(function(el){
		var img = el.getElement('img');
		if (!img ) return;
		
		el.removeEvents();
		if (el.hasClass('selected')) {
			el.setStyle('opacity', .5);
			return;
		}//endif
		
		el.set('tween', {transition: Fx.Transitions.Expo.easeOut, duration: 'short'});
		el.addEvents({
			'mouseleave': function(){
				this.tween('opacity', [.5, 1]);
			},
			'mouseenter': function(){
				this.tween('opacity', [1, .5]);
			}
		});
	});
});