var $optionSets = $('#options .option-set'),

          $optionLinks = $optionSets.find('a');

      $optionLinks.click(function(){

        var $this = $(this);

        // don't proceed if already selected

        if ( $this.hasClass('selected') ) {

          return false;

        }

        var $optionSet = $this.parents('.option-set');

        $optionSet.find('.selected').removeClass('selected');

        $this.addClass('selected');

        // make option object dynamically, i.e. { filter: '.my-filter-class' }

        var options = {},

            key = $optionSet.attr('data-option-key'),

            value = $this.attr('data-option-value');

        // parse 'false' as false boolean

        value = value === 'false' ? false : value;

        options[ key ] = value;

        if ( key === 'layoutMode' && typeof changeLayoutMode === 'function' ) {

          // changes in layout modes need extra logic

          changeLayoutMode( $this, options )

        } else {

          // otherwise, apply new options

          $container.isotope( options );

        }

        return false;

      });