//Add to header
<script src="https://www.dukelearntoprogram.com/course1/common/js/image/SimpleImage.js">
</script>
//Add to body
<script>
let imgcanvas = document.getElementById("preview");
let fileinput = document.getElementById("upload");
fileinput.onchange = upload;
function upload(e) {
var image = new SimpleImage(fileinput);
image.drawTo(imgcanvas);
}
</script>