$('<input type="checkbox" class="form-checkbox" />').prependTo('th.select-all').toggle(function() {
      $('input:checkbox', this.form).each(function() {
        this.checked = true;
        $(this).parents('tr').addClass('selected');

      });
      return true;
    }, function() {
      $('input:checkbox', this.form).each(function() {
        this.checked = false;
        $(this).parents('tr').removeClass('selected');
      });
    });