Auto Slideshow with pure JS

I need to write code for auto slideshow js without library.But i got stuck how to get children of div with class name.(new to web development)

<div class="slideshow">
    <img src="img/kitten_1.jpg">
    <img src="img/kitten_2.jpg">
    <img src="img/kitten_3.jpg">
    <img src="img/kitten_4.jpg">
    <img src="img/kitten_5.jpg">