efecto mover imagen con el teclado mediante javascript

codigo javascript que permite desplazar una imagen cualquiera, mediante el teclado.

Código Javascript


<html>
<title>efecto mover imagen con el teclado</title>
<HEAD>
<script type="text/javascript">
<!-- Original:  Massimo Giari (motore@iol.it) -->
<!-- This script and many more are available free online at -->
<!-- The JavaScript Source!! http://javascript.internet.com -->
<!-- Begin
n = (document.layers) ? 1 : 0;
ie = (document.all) ? 1 : 0;
function moveImage() {
if (n) {
block = document.blockDiv;
}
if (ie) {
block = blockDiv.style;
}
block.xpos = parseInt(block.left);
block.active = 0;
document.onkeydown = keyDown;
document.onkeyup = keyUp;
if (n) {
document.captureEvents(Event.keydown | Event.keyup); 
   }
}
function keyDown(e) {
if (n) {
var nKey = e.which;
var ieKey = 0;
}
if (ie) {
var ieKey = event.keyCode;
var nKey = 0;
}
if ((nKey == 97 || ieKey == 65) && !block.active) {   
block.active = 1;
slideLeft();
}
if ((nKey == 100 || ieKey == 68) && !block.active) {   
block.active = 1;
slideRight();
   }
}
function keyUp(e) {
if (n) {
var nKey = e.which;
var ieKey = 0;
}
if (ie) {
var ieKey = event.keyCode;
var nKey = 0;
}
if ((nKey == 97 || ieKey == 65 || nKey == 100 || ieKey == 68))
block.active = 0;
}
function slideRight() {
if (block.active) {
block.xpos += 5;
block.left = block.xpos;
status = block.xpos;
setTimeout("slideRight()", 25);
   }
}
function slideLeft() {
if (block.active) {
block.xpos -= 5;
block.left = block.xpos;
status = block.xpos;
setTimeout("slideLeft()", 25);
   }
}
//  End -->
</script>
</HEAD>
<!-- STEP TWO: Insert the onLoad event handler into your BODY tag  -->
<BODY OnLoad="moveImage()">
<!-- STEP THREE: Copy this code into the BODY of your HTML document  -->
<!-- This script and many more are available free online at -->
<!-- The JavaScript Source!! http://javascript.internet.com -->
<div id="blockDiv" STYLE="position: absolute; left: 317; top: 127; width: 137; height: 121"> 
<img src="ejemplos/bisco.gif"></div>
<center>
Usa la tecla <b>A</b> para mover la imagen hacia la izquierda, <b>D</b> para moverla hacia la derecha.
<center>

</body>
</html>
Ver ejemplo Javascript en funcionamiento