Display array element in rails

I try to make the two columns list of products, this is my code

<table>
  <% (0..@products.length-1).step(2) do |i| %>
    <tr><td><div id="product_left">
        <%= image_tag @products[i].photo.url(:small) %>
        <%= @products[i].name %><br/>
        Price: <%= @products[i].price %><br/>   
        <%= link_to "details", :action=>"show", :id=> @products[i].id %>
        &nbsp;&nbsp;
        <%= link_to "add to card", {:controller=> "carts", :act开发者_开发问答ion=>"add", :id=> @products[i].id}, :remote=> true %>
     </div> </td>
    <% if @products.length > i %>
     <td><div id="product_right">       
        <%= image_tag @products[i+1].photo.url(:small) %> 
        <%= @products[i+1].name %><br/>
        Price: <%= @products[i+1].price %><br/> 
        <%= link_to "details", :action=>"show", :id=> @products[i+1].id %>
        &nbsp;&nbsp;
        <%= link_to "add to card", {:controller=> "carts", :action=>"add", :id=> @products[i+1].id}, :remote=> true %>
     </div></td> 
     <% end %>
   </tr>
  <% end %>
  </table>

the problem is in the second div, rails give me an error on @products[i+1]. How can I solve it?

---

<table>
  <% @products.each_slice(2) do |products| -%>
    <tr>
      <% products.zip(["left", "right"]).each do |product, side| -%>
        <td>
          <div id="product_<%= side %>">
            <%= image_tag product.photo.url(:small) %>
            <%= product.name %><br/>
            Price: <%= product.price %><br/>   
            <%= link_to "details", product %>
            &nbsp;&nbsp;
            <%= link_to "add to card", [:add, :carts, product], :remote=> true %>
          </div> 
        </td>
      <% end %>
    </tr>
  <% end -%>
</table>

Also you shouldn't use not uniq id. Here you have got multiple product_left and product_right ids. That's not good