指定時間ごとに画像を変更(フィルタ効果付き)

<html lang="ja">
<head>
<title></title>
<script type="text/javascript">
<!--
//変更秒間隔を指定
var sec = 3;
sec = sec * 1000;
arrI = new Array("1.gif","2.gif","3.gif","4.gif","5.gif")
var num = arrI.length;
var arrO = new Array();
for (var i=0;i<num;i++) {
  arrO[i] = new Image();
  arrO[i].src = arrI[i];
}
i = 0;
function cngImg(){
	if(document.all){
		document.images.img.style.filter="blendTrans()";
		document.images.img.filters.blendTrans.Apply();
	}
	document.images.img.src = arrO[i].src;
	if(document.all){
		document.images.img.filters.blendTrans.Play();
	}
	i ++;
	if(i >= num){i = 0;}
	setTimeout("cngImg()",sec);
}
//-->
</script>
</head>
<body onLoad="cngImg();">
<img src="1.gif" id="img" alt="">

</body>
</html>