def admin_variants_json
      render :json => false if !user_is_allowed('products', 'edit')    
      p = Product.find(params[:id])
      render :json => p.variants
    end
def admin_variants_json
      render :json => false if !user_is_allowed('products', 'edit')    
      p = Product.find(params[:id])
      render :json => p.variants
    end
GET /admin/products/:id/variants/json