[bxslider.js] 슬라이드가 여러개일때 .slider-prev, .slider-next 각각 만들기

 $('.tag-slider').each(function() {
   var sliderPrev = $(this).find(".slider-prev");
   var sliderNext = $(this).find(".slider-next");

  $(this).find("ul").bxSlider({
    auto: false,
    pager: false,
    minSlides: 4,
    maxSlides: 4,
    moveSlides: 1,
    slideWidth: 115,
    slideMargin: 3,
    nextSelector: sliderNext,
    prevSelector: sliderPrev
  });
});