window.onload=function(){
	$('nav').childElements().each(function(me){
		me.setOpacity(0.5);
		me.observe('mouseover', function(){
			me.setOpacity(1);
			Effect.Shake(me,{duration:0.6,distance:2});
		});
		me.observe('mouseout', function(){
			me.setOpacity(0.5);
		});
	});
}