select all check boxes javascript

Hi I'm trying to "check all or deselect all" check boxes in my rails app. it does working when I use the checkbox and JS. But, I also want the user the have the same function with links as well. So, when the click on the link it will "check all or deselect all" checkboxes.

Thanks,

 <!-- Split button -->
    <div class="btn-group">
     <button type="button" class="btn btn-warning"><input type="checkbox" id="selecctall" value="selectAll"></button>
    <button type="button" class="btn btn-warning dropdown-toggle" data-toggle="dropdown" aria-expanded="false">
      <span class="caret"></span>
    </button>

    <ul class="dropdown-menu" role="menu">
      <li><a id="selectAll"  title="Click to do something" href="#" onclick="check();return false;">Select All</a></li>
      <li><a id="selectAll" title="Click to do something" href="#" onclick="uncheck();return false;">None</a></li>
    </ul>
  </div>

This is the loop where next to each user I have the checkbox.

<% @users.each do |user| %>
   <tr class="<%= cycle("even", "odd") %>">
    <td><input id= "user_id_<%="#{user.id}"%>" name="user_ids[]" value=<%= user.id %> type="checkbox" class="checkbox1"></td>
    <td><%= user.full_name %></td>
    <td><%= user.email %></td>
    <td>
  <% end %>

This is the js at the bottom of the page

<% content_for :javascripts do %>
      <script >
        function check() {
          if(document.getElementById("selecctall").checked = true;
        }

       function uncheck() {
         document.getElementById("selecctall").checked = false;
      }

     $(document).ready(function() {
        $('#selecctall').click(function(event) {
            if(this.checked) {
                $('.checkbox1').each(function() {
                    this.checked = true;
                });
            }else{
                $('.checkbox1').each(function() {
                    this.checked = false;
                });
            }
        });

     });
     $('body').on('hidden.bs.modal', '.modal', function () {
      $(this).removeData('bs.modal');
     });
   </script>