Shopping Cart Ajax problem

Hello , I am working Agile Web Developement 4th edition .. my problem is about ajax implenmetionwhen I try to use shopping card i got a strange error. When i add first product there is no problem . But if I had second products it add second product and lists 2 times . like :1) 2 * product 1 2) 1 * product 21) 2 * product 1 2) 1 * product 2I guess I  have a  problem with my _line_items.html.erb loop. Can anyone help me to solve this recursive loop problem. <% @cart.line_items.each do |item| %>    <tr>      <td><%= item.quantity %>×</td>      <td><%= item.product.title %></td>      <td class=