script.js

$(document).ready(function(){
  $('.popup-btn').click(function(){ 
    var popupBlock = $('#'+$(this).data('popup'));
    popupBlock.addClass('active')
      .find('.fade-out').click(function(){
        popupBlock.css('opacity','0').find('.popup-content').css('margin-top','350px');        
        setTimeout(function(){
          $('.popup').removeClass('active');
          popupBlock.css('opacity','').find('.popup-content').css('margin-top','');
        }, 600);
      });
 });
}); 

var index = 0;
var slides = document.querySelectorAll(".slides");
var dot = document.querySelectorAll(".dot");

function changeSlide(){

  if(index<0){
    index = slides.length-1;
  }
  
  if(index>slides.length-1){
    index = 0;
  }
  
  for(let i=0;i<slides.length;i++){
    slides[i].style.display = "none";
    dot[i].classList.remove("active");
  }
  
  slides[index].style.display= "block";
  dot[index].classList.add("active");
  
  index++;
  
  setTimeout(changeSlide,2000);
  
}

changeSlide();