JQuery页面图片切换和新闻列表滚动效果的具体实(5)

numRoll = numRoll +_neg;
                //得到当前所看元素序号并改变导航CSS
                if(pPos == undefined&&opts.navId){
                    $navBtns.eq(numView).removeClass('navOn');
                    numView +=_neg;
                    if(numView>=_len){
                        numView = 0;
                    }else if(numView<0){
                        numView = _len-1;
                    }
                    $navBtns.eq(numView).addClass('navOn');
                    numRoll = numView;
                }