Slider otomatik geçiş ve dokunarak geçiş nasıl yapabilirim

<script >
    var slideIndex = 1;
showDivs(slideIndex);

function plusDivs(n) {
    showDivs(slideIndex += n);
}

function currentDiv(n) {
    showDivs(slideIndex = n);
}

function showDivs(n) {
    var i;
    var x = document.getElementsByClassName("mySlides");
    var dots = document.getElementsByClassName("demo");
    if (n > x.length) {
        slideIndex = 1
    }
    if (n < 1) {
        slideIndex = x.length
    }
    for (i = 0; i < x.length; i++) {
        x[i].style.display = "none";
    }
    for (i = 0; i < dots.length; i++) {
        dots[i].className = dots[i].className.replace(" w3-white", "");
    }
    x[slideIndex - 1].style.display = "block";
    dots[slideIndex - 1].className += " w3-white";
} < /script>

var slideIndex = 1;
showDivs(slideIndex);

function plusDivs(n) {  showDivs(slideIndex += n);
}

function currentDiv(n) {  showDivs(slideIndex = n);
}

function showDivs(n) {  var i;  var x = document.getElementsByClassName("mySlides");  var dots = document.getElementsByClassName("demo");  if (n > x.length) {slideIndex = 1}      if (n < 1) {slideIndex = x.length}  for (i = 0; i < x.length; i++) {     x[i].style.display = "none";    }  for (i = 0; i < dots.length; i++) {     dots[i].className = dots[i].className.replace(" w3-white", "");  }  x[slideIndex-1].style.display = "block";    dots[slideIndex-1].className += " w3-white";
}
 setInterval(function(){showDivs(++slideIndex);},3000);

<div class="owl-carousel">
  <div class="item" style="background-image:url(bg.jpg);"></div>
</div>

.item {
background-size:cover;    
background-repeat:no-repeat;    
background-position:top;
width:100%;
height:100%;
min-height:500px;
}