Hi Bontina,
Bontina Chen wrote:
@bts = BT.find_by_product_id(@product.id)
<%=render :partial => "bt/bt", :collection => @bts %>
undefined method `each_with_index' for #<BT:0x45ed70c>
Just change the find to:
@bts = BT.find_all_by_product_id(@product.id)
Best regards, Bill