window.addEvent('domready', function() {
	
	$(document.body).getElements('a.navbutton').addEvents({
	    'mouseenter': function(){
			this.set('tween', {duration: 'short'});
	        this.tween('background-color', '#51AE27');
	    },
	    'mouseleave': function(){
			this.set('tween', {duration: 'short'});
	        this.tween('background-color', '#519332');
	    }
	});
});