var slideIndex = 1; showSlides(slideIndex);  function plusSlide() {     showSlides(slideIndex += 1); }  function minusSlide() {     showSlides(slideIndex -= 1);   }  function currentSlide(n) {     showSlides(slideIndex = n); }  var interval_slides = setInterval(plusSlide,9000);  var tovar = 0;  function showSlides(element_id) {         var element = document.getElementById('id');     var slides = document.getElementsByClassName("item");     var dots = document.getElementsByClassName("slider-dots_item");     if (n > slides.length) {       slideIndex = 1     }     if (n < 1) {         slideIndex = slides.length     }     for (i = 0; i < slides.length; i++) {         slides[i].style.display = "none";     }     for (i = 0; i < dots.length; i++) {         dots[i].className = dots[i].className.replace(" active", "");     }     slides[slideIndex - 1].style.display = "block";     dots[slideIndex - 1].className += " active"; }