window.addEvent('domready', function() {
	
	var btn_array = $$(".link_menu");
	
	btn_array.each(function(el,i){

		el.addEvents({
			'mouseenter': function(){
				this.addClass("mouse_over");
			},
			'mouseleave': function(){
				this.removeClass("mouse_over");
			}
		});	
		
	})
	
	
});