buona-main.js

function prepare_query(event){
    if (Ajax.activeRequestCount == 0) {
        var a = Event.findElement(event, "a");

        var attribute = a.readAttribute('data-attribute') || "";
        var option    = a.readAttribute('data-option') || "";
        
        if(typeof window.layerFilters === 'undefined'){
            window.layerFilters = query2array(window.location.href.split('?')[1]);
        }

        if(a.hasClassName('amshopby-attr-selected')){
            var index = window.layerFilters[attribute].indexOf(option);
            window.layerFilters[attribute].splice(index, 1);
            if(window.layerFilters[attribute].length == 0){
                var index = window.layerFilters.indexOf(attribute);
                delete window.layerFilters[attribute];
            }
        }else{
            if (typeof window.layerFilters[attribute] === "undefined"){
                window.layerFilters[attribute] = [];
            }
            window.layerFilters[attribute].push(option);
        }
        var query = array2query(window.layerFilters);

        a.toggleClassName('amshopby-attr-selected');
        a.toggleClassName('amshopby-attr');
        check_count(query, event);
    }

    Event.stop(event);
    return false;
}