def admin_edit_variant_columns
      return if !user_is_allowed('products', 'edit')    
      @product = Product.find(params[:id])
      session['variant_cols'] = self.default_variant_cols if session['variant_cols'].nil?
      @cols = session['variant_cols']
      render :layout => 'caboose/admin'
    end
def admin_edit_variant_columns
      return if !user_is_allowed('products', 'edit')    
      @product = Product.find(params[:id])
      session['variant_cols'] = self.default_variant_cols if session['variant_cols'].nil?
      @cols = session['variant_cols']
      render :layout => 'caboose/admin'
    end
GET /admin/products/:id/variant-cols