var list = $$('.box');
list.each(function(element) {
 
	var fx = new Fx.Styles(element, {duration:250, wait:false});
 
	element.addEvent('mouseenter', function(){
		fx.start({
			'margin-left': 5
		});
	});
 
	element.addEvent('mouseleave', function(){
		fx.start({
			'margin-left': 0
		});
	});
 
});