Untitled

<!DOCTYPE html>
<html dir="ltr" lang="en">
    <head>
        <title>JavaScript Slideshow</title>
        <style>
        #slider > img { display: none }
        </style>
    </head>
    <body>
        <div id="slider">
            <img src="img1.png">
            <img src="img2.png">
            <img src="img3.png">
            <img src="img4.png">
            <img src="img5.png">
        </div>
        <script>
            var s = document.getElementById("slider").getElementsByTagName("img");
            var c = s.length;
            setInterval(function() {
                s[(s.length++) % c].style.display="block";
            }, 5000);
        </script>
    </body>
</html>

var s = document.getElementById("slider").getElementsByTagName("img");
    var c = s.length;
    setInterval(function() {
        s[c % s.length].style.display="";
        s[(++c) % s.length].style.display="block";
    }, 5000);