$(document).ready(function() {
pic = ["15","17","19","20"];
$.each(pic, function() {
var service_link=".service_link"+this;
var service_pic=".service_pic"+this;
var pic_bg_over="url(assets/templates/kts/images/_service_pic"+this+".png) top right no-repeat";
var pic_bg_out="url(assets/templates/kts/images/service_pic"+this+".png) top right no-repeat";
$(service_link).hover(
      function () {
        $(service_pic).css({"background" : pic_bg_over});
      },
      function () {
        $(service_pic).css({"background" : pic_bg_out});
      }
    );
});
});