anchor.diff:    <% end%>
     </tbody>
   </table>
  -    <div class="center">
  -      <button class="btn btn-large" style="width: 50%; font-weight: bold">Update</button>
  -    </div>
  +<div class="center">
  +  <button class="btn btn-large" style="width: 50%; font-weight: bold">Update</button>
  +</div>
   <% end %>
  
positive.code:   </tr>
    </thead>
    <tbody>
    <% @missions.each do |mission| %>
        <tr>
          <td>
            <input name="missions[<%= mission.id %>][title]" class="input-medium" type="text"  value="<%= mission.title %>" required>
  
negative.code: </div>
  <% if can? :manage, :bulk_update %>
      <ul class="nav nav-tabs">
        <li class="<%= 'active' if @tab == 'missions' %>">
          <a href="<%=  course_missions_path %>?_tab=main" data-toggle="tab"><h4>Missions</h4></a>
        </li>
        <li class="<%= 'active' if @tab == 'overview' %>">
          <a href="<%= course_missions_overview_path %>" data-toggle="tab"><h4>Overview</h4></a>
        </li>
      </ul>
  