Javascript Moving Background

este codigo javascript, nos muestra como mover el Background de nuestra pagina.

Código Javascript


<html>
<head>
<title>Javascript Moving Background</title>
</head>
<body background="backold.gif">
<script language="JavaScript" type="text/javascript">
<!--
// please keep these lines on when you copy the source
// made by: Nicolas - http://www.javascript-page.com
var background = "ejemplos/bisco.gif";
var speed = 0;
browserName = navigator.appName;
browserVer = parseInt(navigator.appVersion);
if (browserName != "Netscape" || browserVer >= 4.5) {
function moveback(movert,movedn,hPos,vPos) {
 
  if (arguments[4])
    document.body.style.backgroundImage = "url(\"" + arguments[4] + "\")";
 
  if (arguments[5])
    document.body.style.backgroundRepeat = arguments[5]
 
  if (!isNaN(hPos)) {
    if ((movert!=0) && (hPos>0)) hPos=-100000
    hPos += movert
  } 
  if (!isNaN(vPos)) {
    if ((movedn!=0) && (vPos>0)) vPos=-100000
    vPos+= movedn
  }
 
  document.body.style.backgroundPosition= hPos + " " + vPos
  if (isNaN(hPos))  hPos = "\"" + hPos + "\""
  if (isNaN(vPos)) vPos = "\"" + vPos + "\""
setTimeout("moveback("+movert+","+movedn+","+hPos+","+vPos+")",speed)
}
 
moveback(1,1,0,0, background);
}
//-->
</script>
</FONT>
</BODY>
</HTML>

Ver ejemplo Javascript en funcionamiento