ahornjs = {
    toggleAncestors: function(ancestors, element, className) {
        // reset className
        ancestors.each(function(item){
            item.removeClass(className);
        });
        // assign className to given element
        element.addClass(className);
    },
    
    cycleThroughList: function(list, className, step) {
       var index;
       // find index of element with given className
       list.each(function(item, i){
           if(item.className == className) {
               index = i;
           }
       });
       
       // forwards
       if(step > 0) {
           if(index+step < list.length) {
               var item = list[index+1];
           }
           else {
               var item = list[0];
           }           
       }
       // backwards
       else {
           if(index+step > 0) {
               var item = list[index-1];
           }
           else {
               var item = list[list.length-1];
           }            
       }
       
       this.toggleAncestors(list, item, className);
    }
}