var Nutrition = new Class({
    els: [],
    id: 'nutrition',
    initialize: function() {
        $(this.id).getElements('div').each(function(el,idx){
            this.els.push(el);
        }.bind(this));
        this.display(0);
    },
    display: function(num) {
        this.hide();
        $(this.els[num]).style.display='block';
    },
    hide: function() {
        this.els.each(function(el,idx){
            $(el).style.display='none';
        });
    }
});