Adding and removing checkbox values to an array not working

I have done this before, but for some reason my current implementation isn't working.

I have some checkboxes and when clicked, I want that value put into an array. When that checkbox is clicked again, I want to remove that value.

HTML:

<div class="fieldwrap form-filters">
  <label for="filter0" class="icon-text checkbox">
      <input type="checkbox" id="filter0" name="filter0" value="Coast" class="hidden" />
    Coast</label>
  <label for="filter1" class="icon-text checkbox">
      <input type="checkbox" id="filter1" name="filter1" value="Great views" class="hidden" />
    Great views</label>
  <label for="filter2" class="icon-text checkbox">
      <input type="checkbox" id="filter2" name="filter2" value="Historic" class="hidden" />
    Historic</label>
  <label for="filter3" class="icon-text checkbox">
      <input type="checkbox" id="filter3" name="filter3" value="Moorland" class="hidden" />
    Moorland</label>
  <label for="filter4" class="icon-text checkbox">
      <input type="checkbox" id="filter4" name="filter4" value="Wildlife" class="hidden" />
    Wildlife</label>
  <label for="filter5" class="icon-text checkbox">
      <input type="checkbox" id="filter5" name="filter5" value="Woodland" class="hidden" />
    Woodland</label>
</div>

JS:

var filter_options = [];

$('.form-filters input:checkbox').click(function() {

    var name = $(this).val().trim();
    var index = filter_options.indexOf(name);
    if (index > -1) {
        filter_options = filter_options.slice(index, 1);
        console.log('Remove: '+name+' at index: '+index);
    } else {
        filter_options.push(name);
        console.log('Add: '+name);
    }

    $('#result').html(filter_options.join('; '));
    console.log(filter_options);

});

DEMO: http://ift.tt/1LDmVHW

For some reason it seems to randomly remove the values, but seems to always add them.

What have I done wrong?